sheetrock over plaster?

[mdb]

I have a 1950's brick home in Virginia with true plaster interior walls and it's time to repaint a stairway wall. The paint is in pretty bad shape. It flakes off easily with the blade of a chisel, with all layers of paint right down to the plaster skim coat coming up. It's as though the paint never really bonded to the original plaster. This failure to bond seems to have occured only on the exterior walls so I wonder if the lack of housewrap and thus colder surfaces might explain the peeling. The task before me is to either scrape all the old paint off or perhaps to paper the wall. But I'm also wondering about adding a layer of 3/8" sheetock directly to the plaster. The plaster wall is quite cold to the touch and I wonder if I'd gain some insulation, especially if I added a layer of some sort of very thin insulation before adding the sheetrock. Back when our home was built, contractors just put lath directly on the brick or block without any additional insulation. I know I'd have to remove molding around windows and at the baseboard, but that's not a huge project. I'm not sure how I'd handle the joint where ceiling meets wall because the ceiling goes off at a 45 degree angle, not the normal 90 degrees.

Would I gain much feeling of warmth with the additional sheetrock? What product would be best for the thin foam insulation? Any new products better than plain sheetrock which I know doesn't have much of an R factor?

Thanks.

[hallerb]

I would blow insulation in walls, you will need 2 holes one near bottom one near top of each stud cavatity, remove all the lose plaster, prime area with kilz oil to help adhesion, then skim coat with drywall compound. it adheres great.

this elminates all the moulding issues, can result in a excellent job and insulation saves energy.

I would look into closed cell foam for that wall its a self vapor barrier, about R6 per inch, theres a minimal expanding type for this application.

I would take a close look for water problems in this area that may be causing the peeling plaster, either wall siding or some sort of roof flashing problem. Mght be worth popening the wall at the worst place and taking a look, you might find a leaking drain pipe or something. I did this recently here for the same reason and found a bath leak, actually 2 that were somehow migrating into this wall nearby and causing plaster peeling

[<aemeijers]

1950s brick with plaster walls could easily be a Real Brick house (no stud cavities)- they were still being built in that era. OP&#39;s comment that the lather may be directly on the brick or block would tend to support that idea.

MDB, please enlighten us- Stick frame or masonry walls?

aem sends...

[Edwin Pawlowski]

When the OP said real brick, I though it was like my last house, masonry walls. Stick frame would be a facade only. The real brick did not leave much room for insulation.

[Michael B]

During the 50&#39;s, it was very common to build without insulating.

I get the impression that the lath and plaster are applied directly to the brick face. Have you considered easing a small drill bit through to the underlying brick to determine thickness, removing the plaster and lath, using an adhesive to secure the right thickness of Tuff-R to the brick, and then similarly attach 3/8 drywall?

The Tuff-R is foil-backed > I have a 1950&#39;s brick home in Virginia with true plaster interior walls and

[Michael B]

[mdb]

Yes, the construction is all masonry. Brick facing with a block core. Plaster lath attached to the block interior surface. The only voids are in the blocks. I did go up into the attic to see if I could see any leakage issues. Nothing. Nor is there any obvious leaking happening on those interior walls. It&#39;s the entire cold wall surface where the original paint flakes away from the skim coat. So I don&#39;t think injected insulation is an option for me.

Thanks

[mdb]

I&#39;m really not interested in tearing out that entire wall. Just too much of a job when the benefit would really only be seen if I did the entire home that way. But what about my original question, the wisdom of applying thin foam (maybe the 1/2 Tuff-R Michael B mentioned) with a 1/2 inch layer of sheet rock on top. Adding that full inch does create issues for windows frames and baseboard moldings but I could probably work it out. Would still like to find something even thinner than the 1/2 inch Tuff-R though.

[Edwin Pawlowski]

If the top of the block is accessible, it is possible to insulate the holes. Not a cure all, but it does help. This is often done on commercial/industrial block buildings.

[Heathcliff]

Of course, the thinner your insulation, the less R-value you are gaining. When you get below an inch, I would start to question whether it&#39;s really worth the extra trouble. That being said, if you want something very thin, you might look at the stuff they sell as underlayment for hardiplank type floors. I think it&#39;s a closed cell foam, it comes in rolls about 4 feet wide and it&#39;s about an eighth- inch thick, IIRC. Dunno what the R-value would be, or even if the package would tell you. -- H

[Michael B]

[Don Young]

Somehow, I feel that a minimum approach to be worthwhile would be 3/4 in. foam board topped with 3/8 in. drywall. That should be easily installed although you would have to build out your window frames and baseboards. Be aware that plastered walls can be very unlevel and out of square.

Don Young