# Stage floor problems



## MusicNinja610 (Jul 9, 2017)

I have recently laid in a new Hardboard floor on our stage. Gave it two coats of flat black and called it good. Well I've had nothing but problems since. Any tape peels up, not just the paint, but the first layer of Hardboard. The slick layer. What can I do? Multiple layers of paint? Some kind of sealant? Anyone ran into this issue before?


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## Amiers (Jul 9, 2017)

Yeah you gotta seal it. I would give it another coat of black and let it dry then seal it. Others will recommend sealant. Personally I like off the shelf sealer from the big box stores.


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## BillConnerFASTC (Jul 9, 2017)

Just to clarify, the failure is not the paint but the hardboard.

Sounds like poor quality hardboard. Clean and repaint is about all I think you can do short if replacing or another layer of hardboard.

Have the hardboard spec? Local big box store?


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## MusicNinja610 (Jul 9, 2017)

Amiers said:


> Yeah you gotta seal it. I would give it another coat of black and let it dry then seal it. Others will recommend sealant. Personally I like off the shelf sealer from the big box stores.


What kinda sealer are we talking about? Like a polyeurathane sealant?


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## MusicNinja610 (Jul 9, 2017)

BillConnerFASTC said:


> Just to clarify, the failure is not the paint but the hardboard.
> 
> Sounds like poor quality hardboard. Clean and repaint is about all I think you can do short if replacing or another layer of hardboard.
> 
> Have the hardboard spec? Local big box store?




BillConnerFASTC said:


> Just to clarify, the failure is not the paint but the hardboard.
> 
> Sounds like poor quality hardboard. Clean and repaint is about all I think you can do short if replacing or another layer of hardboard.
> 
> Have the hardboard spec? Local big box store?


Yeah, from Lowe's. Never head a problem like this before.


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## BillConnerFASTC (Jul 10, 2017)

The problem with the big box stores is they will change suppliers in a second, and no idea of what quality they'll have day to day.

If you have a scrap unpainted, see if tape will pull it apart. I don't think any coating can fix that. 

I see Lowe's site only lists a sub 1/8" and a sub 3/16" and I've always specified 1/4 when doing just a hardboard covering. I'm not sure that would affect your problem. 

Stage floor remain one of the most problematic elements if a theatre.


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## Amiers (Jul 10, 2017)

MusicNinja610 said:


> What kinda sealer are we talking about? Like a polyeurathane sealant?




Yeah that's exactly it. Bill does make a good point about things changing hands but Minwax isn't going anywhere soon and I have had good luck with that. 

He is right as well about the thickness. 

Ideally you should start all over and sand it ,prime it ,paint it twice , and seal it twice. 

With the way new paint is being made allow ample time for drying usually 24 hours. 

You literary could have a paint watching party lol. GL

Also don't swear at Ron he is old and might misread into it.


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## BillConnerFASTC (Jul 10, 2017)

I strongly recommend against sanding hardboard. The theatre consultants just discussed this and are nearly unanimous in never sanding at least new hardboard, and sanding old is a last resort.

I'm unclear how the poly will help since the failure seems to be not a coating but interlayer in the hardboard. If the paint and top layer of hardboard peel, what will the poly do? It sure won't penetrate the hatdboard.


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## Amiers (Jul 10, 2017)

Poly is a great sealer and provides that extra layer of protection creating a slick non abrasive surface that *shouldnt* pull up. Depends on the tape. 

Really it comes down to what he laid down. 

If the paint was applied wrong I would most definitely sand the areas of issue and start from scratch or you will just be painting over chipped/pulled paint that over time will just crack and peel. 

Guess we play the waiting game for some answers.


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## BillConnerFASTC (Jul 10, 2017)

Amiers - the paint coatings are not failing as I understand it. The hardboard is pulling apart. If you want the tape to not pull apart the floor, use different tape or wax the floor so the weakest bond is the tape to top coat. If the same tape sticks to poly, that will still pull floor apart.


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## Amiers (Jul 10, 2017)

BillConnerFASTC said:


> Amiers - the paint coatings are not failing as I understand it. The hardboard is pulling apart. If you want the tape to not pull apart the floor, use different tape or wax the floor so the weakest bond is the tape to top coat. If the same tape sticks to poly, that will still pull floor apart.




I feel if the paint process was applied properly primed painted sealed with cure times in between the issues would be resolved as it would provide a good layer of protection regardless of the hardboard used.


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## sk8rsdad (Jul 10, 2017)

One of our floors has the same problem. The paint adheres but the hardboard fails. 

A national distributor for theatre products including spike tape said she has seen the issue more frequently lately and thinks something has changed in the way hardboard is being made. Maybe they've got some "green" formulation that doesn't bond the fibers as well as it used to?


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## BillConnerFASTC (Jul 10, 2017)

So I thought I'd call one of the manufacturers. Those days are probably gone. So far I can only find one in US - Stimson. http://www.stimsonlumber.com/products/hardboard/hardboard/ Good downloads there. I found 5 members of the American Hardboard Association - but it appears only Stimson makes the basic 4 x 8 sheets - the rest all ake products of hardboard or mostly other panels of all sorts - but not hardboard. Chased another source based on data sheet at Home Depot site - looks South American. HD calls it tempered but the manufacturer does not claim to make tempered hardboard.

The more things change, the more they change.


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## MusicNinja610 (Jul 10, 2017)

BillConnerFASTC said:


> So I thought I'd call one of the manufacturers. Those days are probably gone. So far I can only find one in US - Stimson. http://www.stimsonlumber.com/products/hardboard/hardboard/ Good downloads there. I found 5 members of the American Hardboard Association - but it appears only Stimson makes the basic 4 x 8 sheets - the rest all ake products of hardboard or mostly other panels of all sorts - but not hardboard. Chased another source based on data sheet at Home Depot site - looks South American. HD calls it tempered but the manufacturer does not claim to make tempered hardboard.
> 
> The more things change, the more they change.


Bill, this sparked my interest, I did a little more investigating and I'm really starting to wonder if the Hardboard we layed wasn't tempered, or at least the tempering process was cheap. Im not sure where the stuff we used was bought...probably Lowe's or Carter Lumber...if that's the case...I'm not sure what can be done. It may just keep peeling. My thought is to put down a layer of 1/8" maso that is properly tempered and paint that then. It'd save me from having to pull up all the old stuff.


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## dbaxter (Jul 10, 2017)

I think the tempering is the basic problem. Paint on non-tempered tends to soften and separate the hardboard in my experience. When you get the tempered stuff, let it sit in your theater for several days to adjust to your humidity level before you fasten it down (also my experience).


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## BillConnerFASTC (Jul 10, 2017)

Tempering is basically warm oil bath to make it more resistant to moisture. I think I've read you're suppose to prime untempered with oil base. Would not hurt to prime all hardboard with oil base. 

I'd still try to find a piece of what you used and experiment. Tape. Water. Etc. 

But to solve you problem - yes - recover. Somewhere there is a good document on this - a deceased professor from Pennsylvania iirc. It's about spacing, acclimating, fasteners, and paint.


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## RonHebbard (Jul 10, 2017)

dbaxter said:


> I think the tempering is the basic problem. Paint on non-tempered tends to soften and separate the hardboard in my experience. When you get the tempered stuff, let it sit in your theater for several days to adjust to your humidity level before you fasten it down (also my experience).


The last time I received and laid approximately 24 sheets of 4' x 8' x 1/4" double tempered Meso' ( Tempered on both sides ), I was shocked to find they were of differing lengths, differing widths and, WORST OF ALL, they were rhomboid [Not cut with 90 degree corners]
All ordered at the same time, from the same supplier and delivered on the same truck.
Sides were parallel to sides and ends parallel to ends on MOST, but not all, of the sheets.
Some sheets had non parallel sides thus they were narrower at one end than the other.
Finished lengths and widths were inconsistent by between 1/16th to" to 1/8th" over the length and / or width of the sheets.
Discovering MOST of the corners were lesser or greater than 90 degrees by enough to matter was the worst part of laying the Meso'. "They" taped the differing widths of seams and applied two coats of a high-pigment (designed to be thinned with water) black "egg-shell" paint and the Meso' was only down for five weeks in total: The last 2.5 weeks of rehearsal plus 3 weekends of performances. I won't speak to painting and sealing as neither are my expertise.
How to lay / secure in place: Double sided tape, vs. ring nails vs. counter-sunk flat head screws has been beaten to death here in lengthy posts and I won't delve into it. All I'll mention is "they" (Those in charge and calling the shots) intended to slit or remove the masking tape, then lift the floor and store for future use.
Short version: What remained post strike was trash. Most of the tape was pretty much destroyed over the five weeks. Most of the tape brought the surface with it if "they" attempted to remove it NO MATTER HOW CAREFULLY. Less than 6 sheets were worth saving. The remainder came up in so many broken chunks with SERIOUS surface wear in heavily blocked locations that they weren't worth saving to cut down for any appreciable future use.
*Bottom* *Line*: Five weeks and less than 6 sheets were worth saving.
To quote a previous poster: "That was my experience"
As to allowing time for moisture content to acclimatize: I've seen this work to great success with luan mahogany sheets in another venue. The Meso' I've mentioned above was laid flat on the unused auditorium floor and periodically flipped over to expose alternate sides over the course of 4 to 5 days where it was free from foot traffic prior to being transferred to the stage deck for laying. [And then the fun began as we tried to make a respectable deck from a delivery of strangely mis-matched sheets]
Toodleoo!
Ron Hebbard.


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## MusicNinja610 (Jul 11, 2017)

dbaxter said:


> I think the tempering is the basic problem. Paint on non-tempered tends to soften and separate the hardboard in my experience. When you get the tempered stuff, let it sit in your theater for several days to adjust to your humidity level before you fasten it down (also my experience).


And that's what I'm experiencing...I have a feeling the sheets we were given to lay, we're noon treated. Whether that is the purchasers fault or the fault of whichever store we bought it from I don't know.


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## BillConnerFASTC (Jul 11, 2017)

How long since you painted it?

And if you want to experiment in an effort to not have to recover, try coating and area with an oil based primer - I like teh BIN products but does not matter and not sure any alkyd paint with a touch of thinner wouldn't be as good - but maybe a 4x4 area where the wood has pulled up and where it has not. Let it dry 24 hours and coat with your floor paint (ROSCO Tough Prime? PPG Break Through? other?) Let that dry probably 3 days - and then see if you can get tape to pull it up. I like a steel caster with some load back and forth across tape to really test it but find a dance student in hard soled shoes to work on it. If you have the time....


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## MarshallPope (Jul 11, 2017)

For my own curiosity what color is the hardboard? 



I've seen the lighter type commonly in the Northeast and have had MUCH more of a peeling problem than the darker type that I've seen more commonly in the South.


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## Apmccandless (Jul 12, 2017)

As to color I thought that the darker was tempered and the lighter was untempered. Someone earlier mentioned double tempered. What does that mean? Was it run through hot oil twice? Does that help? 
In my many adventures in flooring I have found that the darker the tempered flooring the better restistance to wear and tear. There is one brand available at some Lowe's or Menards in St Louis (each branch in town has a different lumber supplier so selection and brand of lumber varies by store) that has radiused corners. It is 3/16" thick and smooth both sides. I have used this indoors and out and had very good luck with paint adhesion and I don't recall this ever having an issue where tape ripped up the flooring. On the other side of the issue Eucaboard brand has been an issue several times when I have used it for flooring. I don't know if it is a different Tempering process or if the screen back somehow allows moisture in that the smooth back does not. I have had it tear when I removed the gaff tape I used to hold the sheets together. In my experience I would agree that you are suffering a material issue not a paint issue.


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## RonHebbard (Jul 12, 2017)

Apmccandless said:


> As to color I thought that the darker was tempered and the lighter was untempered. Someone earlier mentioned double tempered. What does that mean? Was it run through hot oil twice? Does that help?
> In my many adventures in flooring I have found that the darker the tempered flooring the better resistance to wear and tear. There is one brand available at some Lowe's or Menards in St Louis (each branch in town has a different lumber supplier so selection and brand of lumber varies by store) that has radiused corners. It is 3/16" thick and smooth both sides. I have used this indoors and out and had very good luck with paint adhesion and I don't recall this ever having an issue where tape ripped up the flooring. On the other side of the issue Eucaboard brand has been an issue several times when I have used it for flooring. I don't know if it is a different Tempering process or if the screen back somehow allows moisture in that the smooth back does not. I have had it tear when I removed the gaff tape I used to hold the sheets together. In my experience I would agree that you are suffering a material issue not a paint issue.


 @Apmccandless "Someone earlier mentioned double tempered. What does that mean?" I @RonHebbard believe you're referring to my post where I recall explaining suppliers in my area refer to Meso' which has been tempered on both sides as "Double tempered". 
Toodleoo!
Ron Hebbard.


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## BillConnerFASTC (Jul 12, 2017)

From woodworkers journal
*"How do I tell regular hardboard (Masonite) from tempered hardboard, and what are the differences between the two?
Timothy Knight:* Hardboard is a generic term for a panel manufactured from cellulose fibers pressed together under extreme pressure and heat to a density of at least 31 lbs per cubic foot. The natural lignin in the wood fibers acts as the bonding agent. The wet process using steam originated from the original patent of William H. Mason in 1926 and 1928. Most all hardboard today is manufactured using the “Mason” process, although hardboard made by the Masonite Company itself is sold under the trade name “Duron”. Tempered hardboard adds an additional step of coating the hardboard with a thin film of linseed oil and baking the board to give more water and impact resistance, hardness, rigidity and tensile strength. Tempered hardboard is used almost exclusively in construction siding. The manufacturer should be able to tell you if their particular hardboard is tempered or not.
*Carol Reed:* Visually, tempered hardboard is much darker, due to the oil."

Ive heard the term double tempered but sense it might be marketing hype.

Whether its screened on one side or not (smooth one or both sides) seems to be a factor of wet (screened) or dry (smooth both sides) processes. I have seen screened side used for "fine art" paintings.


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## MusicNinja610 (Jul 12, 2017)

MarshallPope said:


> For my own curiosity what color is the hardboard?
> 
> 
> 
> I've seen the lighter type commonly in the Northeast and have had MUCH more of a peeling problem than the darker type that I've seen more commonly in the South.


It's lighter. I'm believing more and more that it's un tempered. Which I imagine is why I'm having this problem.


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## teqniqal (Jul 13, 2017)

You get what you pay for. Attached is the information you need to have to select and order tempered hardboard. This defines what you are looking for in properties. The Big Box stores all carry the worst possible grade (Class 5) by default. You have to special order anything better. You have to verify it upon receipt (don't trust them to ship the right thing). 1/4" Sierra Pine Medite II or Medex products seem to be good products and are orderable (albeit, with some lead-time) - they are in the range of Class 1 & Class 2. I consider it a modern day replacement for the Masonite Duron WR, which, at one time, was used on many professional stages. Investing in a good quality top layer is prudent, if properly maintained it can last twenty or more years. What damages a good quality floor material is moisture (from leaking roofs or wet paint -- damp mopping should not affect it) and impatient techs that try to drive nails or staples into it in lieu of using sand/shot weight bags or improved stage screws to secure scenery. Teach people how to properly anchor things to the floor and your floor will last longer. Charge them for it if they do it wrong. And charge them twice as much as the last time if they repeat it, etc. Eventually, they will learn.

As to the floor finish, I find that the Madison Chemical Company Gemthane STC (Stage Top Coat) with their recommended Gemthane MG-201 Sealer primer makes for a very tough finish that won't peel off the face of the hardboard. If properly maintained the finish can last five-to-ten years.

The constant repainting of the floors is typically due to people painting directly on the stage floor in lieu of installing a scenic drop cloth and painting it instead. Yes, the drop cloth takes time (Labor + Materials = Money), but it saves having to constantly refinish the floor, or worse, replace the floor. Discourage anyone from painting on the floor. Charge them (a lot) for it if they do. And charge them twice as much as the last time if they repeat it, etc. Eventually, they will learn.

Oh yeah, don't forget about user's that want to tap dance on your floor. One answer: NO. Insist that they lay-down a protective layer of dance vinyl (Rosco, Harlequin, etc.) or additional tempered hardboard. If you want to damp the clackity-clack sound, then the cheap Big Box store hardboard will do nicely (as it flakes apart).  If you want a brighter, crisper sound, then the harder (ANSI Class 1 or 2 ) hardboard may be more appropriate. A 1/8" layer that is temporarily secured with gaffer's tape will suffice to protect your floor from tap shoes.

Glitter can be a problem, too. It can get stuck / embedded in the cheaper (softer) hardboards and cheaper (softer) paints (two good reasons to use harder hardboard and better paint). First answer is: *NO GLITTER!* Back-up plan (should it be introduced onto your stage): Is to clean it up immediately (and charge them heavily for the clean-up), being sure to vacuum-up as much as possible (maybe even Q-Tip swab the cracks and screw heads). The longer it stays around, the more it gets crushed into the surface and tracked around your theatre. Don't forget to clean the lights, battens, and soft goods if the glitter got tossed upwards, otherwise it will migrate back to the floor and 're-infect' it.

Speaking of infection, a clean stage that has been regularly damp-mopped is a healthier stage. Keeping the stage free of tiny granules of grit and dirt (and the occasional glass shards, staples, tacks, and wood shavings / sawdust) will keep the floor finish from becoming marred and scarred. As dancers perform, they sweat and in many performances they leave sweat beads all across your floor. If they are doing modern dance they may be sliding or rolling on the floor surface. They both deposit contaminants and pick-up skin diseases and bacteria left by others. During dance shows frequently damp-mop with disinfectant to keep the floor clear of debris, germs, and possibly blood (nicked skin, unexpected bloody noses, etc.);and then immediately dry-mop it to keep from being slippery. A good quality floor surface will make this an easier task. A spongy porous floor will just be a breeding ground for biological contaminants.


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## Allana (Jul 20, 2017)

We definitely had this problem with our hardboard floor. After 3 years of bickering between installers, they decided ultimately that hardboard was simply the wrong floor for the job. The major points of failure where high traffic zones that took plenty of 1-ton road cases rolling across them. The weight caused the hardboard layers to crack apart from each other below the surface of the paint and no matter the manufacturer, nothing can be done with that. 

Paint was also a point of failure, especially when it came to gaff tape. The oil-based paint/primer that was speced for the renovation is more than $100 per gallon but only sold in California (by the pallet). It's dry within 24 hours but recommends 2 weeks of absolutely no-use to properly cure (and something like 5 coats; 2 prime + 3 black). A sealer was not speced as it was supposedly built into the paint. Try as we might, we were unable to find a time in our roadhouse schedule to accommodate the wait time on that paint job and it seems likely we would similarly not be able to find that time every-other year when it would need it.


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## AVerderyAerialRigging (Jul 20, 2017)

Waaaaay back when I was the Head Carp for the NYC run of BatBoy the Musical we had the same exact problem. I don't think that the core cause is cheap hardboard as we used pretty high end tempered Masonite on our deck and we still wound up with a really attractive patch of exposed brown fiber as more of the temper peeled up every night. Until management coughed up the money to replace the sheets in the area, the solution was for me to go out before the show overnight with a can of black spray paint. It looked awesome. Anyways, this is exactly what caused the problem: rather than pay for 'fancy-dancy scenic artists' (GM's exact words), she let the Assoc Set Designer do it with one of his friends. So don't ever do that!

Seriously though, they applied 2 coats of black and 1 coat of sealer, but failed to wait long enough in between the coats for the paint to fully dry, thusly when the paint and the sealer so-mingled (that's what they call it these days, right?) they penetrated the poor hardboard right through the protective sheath of the temper. And that's how peeley patches are made, boys and girls. 



MusicNinja610 said:


> I have recently laid in a new Hardboard floor on our stage. Gave it two coats of flat black and called it good. Well I've had nothing but problems since. Any tape peels up, not just the paint, but the first layer of Hardboard. The slick layer. What can I do? Multiple layers of paint? Some kind of sealant? Anyone ran into this issue before?


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## teqniqal (Jul 21, 2017)

" The major points of failure where high traffic zones that took plenty of 1-ton road cases rolling across them. The weight caused the hardboard layers to crack apart from each other below the surface of the paint and no matter the manufacturer, nothing can be done with that."

I encourage you to re-read the attachment to my prior post. The high-grade tempered hardboard is pretty-much indestructible and fairly water impervious. I suspect that you may be confusing 'manufacturer's brand' with 'manufacturer's product'. Most companies make a cheap (low quality) version for those that don't understand the implications of using poor quality products (obviously, you have experienced the down-side of this choice), and higher quality products for those that have demanding requirements (longevity, load capacity, moisture resistance, etc.). When Masonite Corp made 'masonite', it was available in many different grades. The cheap flake-apart type was the most common, but they also made 'Duron WR' which was used in places like Radio City Music Hall. Your comment about the hardboard cracking apart below the surface pretty much describes the lowest grade tempered hardboard you can buy. The dense stuff, Class 1 & Class 2, is so hard that you can bend a nail if you try to drive it into it (please don't!). This is what you need to deflect the point loads of heavy road cases and scenery rolling on casters. Contact Sierra Pine and have them send you some samples of their Medite II for evaluation. 

That said, the sub-floor decking (typically 2-3 layers of 3/4" plywood) below the sacrificial top sheets (the Class 1 or Class 2 tempered hardboard) must be arranged so that the joints (edge-to-edge seams) on each layer are not coincident to the joints of the layers above or below them. This distributes the shear forces from allowing them to all happen at a common joint. You have to offset the joints layer-to-layer about 8-12". This offset should account for multiple layers so you don't end-up with the joints of layer #1 and #3 being coincident, too. A sprung stage floor should 'give' monolithically, not just at local point loads.

Also, note that I referred the top floor sheathing layer as 'sacrificial'. Replacing an entire stage floor, substructure and all, can be very expensive and with the exception of severe water damage (sustained immersion due to standing water after a flood) or fire, most stage floor substructures are fairly durable (well, unless someone used chip-board, or particle board; or if you get a termite infestation) and it is only the top layer of tempered hardboard that needs to be replaced occasionally. So the top layer is 'sacrificed' to protect the softer wood layers underneath it from the abuse we call 'theater'. I typically specify 1/4" thick material as a good substructure will support this without cracking or other deformations. If your sub floor is softer or more flexible (some basket-weave subfloors are very cushy), you may need a thicker material (or a replacement of some of the sub-floor, too). I know some other consultants that specify the 1" thick materials 'to be sure it doesn't fail', but IMHO, I think that sort of defeats the purpose of the 'sacrificial' layer. That 1" thick stuff is veeeeery expensive. The subfloor should bear the load, the top sacrificial layer is to bear the point loads.

"After 3 years of bickering between installers, they decided ultimately that hardboard was simply the wrong floor for the job." It sounds like the wrong people were installing it (and maybe the particular hardboard was the incorrect type), but someone gave the installer the authority to make an uninformed decision. It would be interesting to see the original drawings and specifications for the floor to see if the design was problematic, or if it was the installers that compromised the final installation. Just like everything else in the theatre, a good spec can be misinterpreted and no one catches it until it is too late. I have walked onto many construction sites and seen the 'el cheepo™' flake-apart generic 'masonite' from the big box store being installed in lieu of the specified flooring product. The flooring contractor seemed to think that once it was painted black that no-one would be the wiser . . . well, until I showed-up. They got to eat the cost of installing and painting the floor TWICE, and were penalized for delaying the project. Sadly, I find too may Architects or Building Owners that don't have the spine to stand-up to a contractor when they blatantly disregard the specifications, so they get walked all over like a cheap rug. As their consultant, all I can due is advise them of the transgression - it's up to them to do something about it.


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## BillConnerFASTC (Jul 21, 2017)

For some of the issues noted, I only specify plyron, which is made with a good grade of hardboard. I have no record of failure of the hardboard.


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## teqniqal (Jul 27, 2017)

teqniqal said:


> As to the floor finish, I find that the Madison Chemical Company Gemthane STC (Stage Top Coat) with their recommended Gemthane MG-201 Sealer primer makes for a very tough finish that won't peel off the face of the hardboard. If properly maintained the finish can last five-to-ten years.



I just learned that Madison Chemical was bought-out by another company and they have discontinued Gemthane STC. (Sadness . . .)

I have been researching other paints, so the back-up plan is to recommend Sherwin Williams ArmorSeal 8100 Epoxy Floor Coating in the color 'SW 2936 Black Emerald', satin finish (not 'gloss' finish). This is a two-part epoxy with a low sheen look.


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## MusicNinja610 (Jul 28, 2017)

teqniqal said:


> You get what you pay for. Attached is the information you need to have to select and order tempered hardboard. This defines what you are looking for in properties. The Big Box stores all carry the worst possible grade (Class 5) by default. You have to special order anything better. You have to verify it upon receipt (don't trust them to ship the right thing). 1/4" Sierra Pine Medite II or Medex products seem to be good products and are orderable (albeit, with some lead-time) - they are in the range of Class 1 & Class 2. I consider it a modern day replacement for the Masonite Duron WR, which, at one time, was used on many professional stages. Investing in a good quality top layer is prudent, if properly maintained it can last twenty or more years. What damages a good quality floor material is moisture (from leaking roofs or wet paint -- damp mopping should not affect it) and impatient techs that try to drive nails or staples into it in lieu of using sand/shot weight bags or improved stage screws to secure scenery. Teach people how to properly anchor things to the floor and your floor will last longer. Charge them for it if they do it wrong. And charge them twice as much as the last time if they repeat it, etc. Eventually, they will learn.
> 
> As to the floor finish, I find that the Madison Chemical Company Gemthane STC (Stage Top Coat) with their recommended Gemthane MG-201 Sealer primer makes for a very tough finish that won't peel off the face of the hardboard. If properly maintained the finish can last five-to-ten years.
> 
> ...




teqniqal said:


> You get what you pay for. Attached is the information you need to have to select and order tempered hardboard. This defines what you are looking for in properties. The Big Box stores all carry the worst possible grade (Class 5) by default. You have to special order anything better. You have to verify it upon receipt (don't trust them to ship the right thing). 1/4" Sierra Pine Medite II or Medex products seem to be good products and are orderable (albeit, with some lead-time) - they are in the range of Class 1 & Class 2. I consider it a modern day replacement for the Masonite Duron WR, which, at one time, was used on many professional stages. Investing in a good quality top layer is prudent, if properly maintained it can last twenty or more years. What damages a good quality floor material is moisture (from leaking roofs or wet paint -- damp mopping should not affect it) and impatient techs that try to drive nails or staples into it in lieu of using sand/shot weight bags or improved stage screws to secure scenery. Teach people how to properly anchor things to the floor and your floor will last longer. Charge them for it if they do it wrong. And charge them twice as much as the last time if they repeat it, etc. Eventually, they will learn.
> 
> As to the floor finish, I find that the Madison Chemical Company Gemthane STC (Stage Top Coat) with their recommended Gemthane MG-201 Sealer primer makes for a very tough finish that won't peel off the face of the hardboard. If properly maintained the finish can last five-to-ten years.
> 
> ...


Hey man, this was a hell of an essay! Thanks for all the info. I appreciate it, especially the Hardboard grading attachment. I didn't realize there were so many variations in grade. Have a good one!


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## BillConnerFASTC (Jul 28, 2017)

I talked to another consultant today and they been seeing this problem increasing - inter layer failure - and they finally reached the tech departments of some hardboard manufacturers. Due to EPA rulings, the process for manufacturing hardboard has changed, or specifically the process that resulted in a high modulus of rupture has been banned. This is just in the past year or two. The growing concensus is that this issue will not improve soon.


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## Rose Steele (Jul 28, 2017)

I also spoke to some manufacturers, and was told the change in manufacturing took effect in 2010, so I fear that's not the answer. Research indicates that requiring "tempering" is not enough. It needs to be tempered to Class I standard, i.e. oil-tempered, not just heat tempered. I wasn't told about any newer changes in allowable procedures. I also found out that most lumber manufacturers don't actually make hardboard; they all seem to buy it from DPI (Decorative Panels Inc), so it's all the same product anyway. I'm told that DPI still has two classes of tempering "service tempering" and class I or oil tempering. Further research needs to be done.


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## teqniqal (Aug 3, 2017)

UPDATE: SierraPine was purchased by Roseburg Forestry Products. The product names are the same, so if searching for information and samples, look for Roseburg Medite II, not SierraPine Medite II.

Alternate products to look at are: Hutton Forest Products 'West Pine Ranger Premium Plus' and Weyerhaeuser (formerly Plum Creek) 'Super-Refined MDF2'.


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