Painting celotex

Any ideas on how to paint celotex? The shop I've inherited (on the corner of our lot) was finished with celotex. I've tried painting it, but it is really absorbent. Also, where there had been water leaks from the ceiling, the celotex is discolored, and paint doesn't cover the stains. My intent is to paint it white to brighten up the shop. I've been using a brush and roller, and I'm considering spraying paint in the future.

Reply to
William Andersen
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You mean the Celotex insulation? If you're talking about the rigid foam insulation, the manufacturers and code usually require it to be covered by something like 1/2" drywall. It's basically tinder on your walls. What exact product do you have? Since your shop is near the property line (inferring that from 'on the corner of our lot') your local codes may be more stringent than if it were elsewhere on the property. Depends on your zoning, etc. More details would be helpful.

R
Reply to
RicodJour

It has been decades since I saw that on walls and even longer since painting it but IIRC it was oil prime, paint.

Reply to
dadiOH

I think he has a material that was used in the 40s and 50s that was made from plant residue. In Hawaii (where I was) they used bagasse which is what's left of sugar cane after being de-juiced. Might have been spelled "cellutex".

It came in 4x8 foot sheets like drywall and was used a lot for ceilings. Had a slightly rough surface, very light. I've also seen it for walls in sheets that had a phony shiplap appearance.

No idea about how flamable it was but I'm guessing it had some sort of fire retardant incorporated into it.

Reply to
dadiOH

Shellac. Give it a good coat of shellac. You can then paint over the shellac and the stains won't bleed, or at least not as badly.

Reply to
Charlie Self

I have an attached garage with my shop in it. The wall between the house and the garage is sheathed in 1/2" thick Celotex. Its really light weight crappy stuff. Holes have been punched in it throughout. Mice have gotten into the wall and tunneled through the insulation. I wouldnt recommend it to anyone. But its been painted a very cheery yellow ever since before I've owned the house for 10 years. So it is possible to paint it.

BTW, nowadays code requires 5/8" firestop drywall so this past summer I ripped it all off the wall, did a bit of electrical work in the wall, and put up drywall. Looks much nicer without the yellow.

-dickm

Reply to
dicko

I'm pretty sure it's celotex. Not a smoothe surface and very light - it was white in 1940. It may have been put up for it's insulation value; I thought it was to provide an interior wall. I don't know about the code. It's already been painted with several different kinds of white paint. It looks better than before it was painted and is brighter but still pretty crappy looking. I may replace it with wall board, since I'm probably going to rewire the building, and service to it. If I do that, I'll insulate the walls first.

Reply to
William Andersen

If you want to use shellac try Zinsser BIN. Its a shellac based sealer that will give it a bright white finish.

Reply to
Roger amd Missy Behnke

Reply to
William Andersen

messagenews:GIKOi.8$ snipped-for-privacy@newsfe06.lga...

Bullseye shellac by Zinnser will do it. Available in big box builder supply stores for about 12-15 bucks a gal. I have used it numerous times to paint and seal andcover stains on ceiling tiles which are typical of celotex type material without the asphalt added. Celotex was an original material put out by Johns-Manville and was made from processed corn stalks and leaves, and used for insulated sheathing on homes etc. Usually sold in 1/2 x 4 x 8 sheets but they also offered a

25/32 or 1" thickness in tongue and groove sheets of 24" x 96" as well.......
Reply to
eekamouse

They aoso made a product called Upsom board which was a white colored sheet that was commonly used for interiior walls prior to sheetrock days, and there is also a product called Homosote which came in a variety of colors but most commonly a grey color which is pretty well rot proof and was used for sofits and outside porch ceilings as well as inside walls and ceilings. Both upson board and homosote are light in weight and available in various thickness when it was made. Both sucked up paints quick and shellac was a common primer used on it back then.

Reply to
eekamouse

In the 1940, during the building boom there were a number of products that competed for the low end market to replace expensive plaster. Most were lightweight cardboard materials about 1/2" thick, even drywall started out in this market and won.

The cellulose boards are similar to fiber ceiling tiles that are still sold today for t-bar ceilings and it is still made as an asphalt impregnated exterior wallboard to use under vinyl siding or brick veneer, although a number of better products are in use today.

Reply to
EXT

Thanks for all of the replies. Since I plan on rewiring the shop (some of the wire is the original fuzzy fabric coated stuff and some is two wire only) I'll probably salvage what celotex I can for the ceiling and then insulate the walls and cover them with dry wall. My wife thinks that's a good idea, I can learn and practice working with dry wall in the shop. I guess she has plans for the housse that she hasn't told me about yet. The shop is 90' from the house and the electric service is under ground. How deep is anyone's guess. My father-in-law sometimes took shortcuts and sometimes went way beyond what's necessary for a good job: I never know what to expect when I look at some of his work. I've been replacing the 2 hole outlets with 3 hole outlets, but most of the wire is only 2. I plan on running new service to the building and replacing the 2 glass fuses with a new service box and probably 4 circuits. The existing 2 means if both main light fixtures are on, you won't be in the dark if 1 blows. I'll check with an electrician, but I'd like to have 2 for lights and a couple of outlets, 1 for my Shopsmith, 1 for ...

Reply to
William Andersen

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