Styrofoam ceiling

[Dave]

I am renovating a room with a concrete ceiling. Previous ceiling (wood paneling) had been removed. The concrete ceiling is a bit uneven and requires smoothing which I'd rather not do.

I am thinking of paneling the ceiling with styrofoam sheet about two inches thick. I 've got some good quality styrofoam (smooth - not grainy) I coul just glue there.

My question is about the lights. I haven't yet selected any lights but other rooms have recessed halogens lights eyebulb style.

Halogens tend to get hot and styrofoam could melt . How much room should I cut for the 50w lights? (a ball park estimate)

[JoeSpareBedroom]

I'm just guessing, but I BELIEVE styrofoam would create some very interesting fumes in a fire. You'd better research this carefully. If I were you, I'd check the building code in your town, and maybe speak to someone at a real building supply dealer. Not Home Depot, not Lowe's. A real supplier.

[ransley]

Hide quoted text -

Foam offgasses for maybe years, it must be sealed and its hard to do. You also must seal it perfectly tight with no air allowed behind it or condensation and mold will occure, it happened to me. 2" of red or blue is only R 11. Foilfaced polyisocyanurate is R 14.4. Foam also does not allow moisture through, working with foams takes planning and knowledge. Do it wrong and you can create many problems down the road.

[JoeSpareBedroom]

The OP is not talking about insulation quality. He wants to use styrofoam to smooth an uneven ceiling, and then, melting it with halogen lights.

Heh. :)

[JoeSpareBedroom]

Time out! Let's see if I'm understanding you correctly: You're going to glue styrofoam directly onto the ceiling, and then install recessed lights? How? In what hollow space?

[Rodger]

Maybe they're going to put up a foot and a half of foam?

a

[Rodger]

Maybe they're going to put up a foot and a half of foam?

- Rodger

[JoeSpareBedroom]

All I can think of right now is idiot campers, starting their campfires using styrofoam plates & cups as kindling. Blech.

[Edwin Pawlowski]

Not a good idea. Styrofoam is a very good insulation, it is made of a flame retarding material, but, according to building code it must be covered with something like drywall. It is not allowed to be exposed. Personally, I'd not use recessed lighting in foam as the light will get very hot, the insulation will trap the heat and probably melt.

[larry moe 'n curly]

No offense, but are you nuts??? Exposed styrofoam is a major fire trap.

Styrofoam burns so badly that almost every locality forbids it to be left exposed, but even if there isn't any law against that, you still want it covered with something highly fire resistant, like plaster or sheet rock. Recessed lighting is bad enough for causing fires even when it's housed properly and surrounded by fireproof insulation with adequate clearance from the light.

[Dave]

[Dave]

This is a warm ceiling bottom floor (two floor house). I am thinking of covering it with a few layers of paint and perhaps some ceiling wallpaper.

The lights is what is a problem. Maybe I should cut enough space or add a an empty space between the stryrofoam sheet and the concrete ceiling.

I've seen many types of stryfoam mouldings and sheets sold in stores so what is the big deal of not being able to leave it exposed or just painted.

[Dave]

I get your point and understand that there must be some space left between the sheets and the recessed lights. That should still lead to warmth buildup. I must need a hollow space between ceiling and the styrofoam.

Like I said I am asking for advice.

[JoeSpareBedroom]

You are completely missing the point. When you checked your local building code, what did you find out about interior use of styrofoam?

Oh...wait: You haven't checked the code yet, have you?

[JoeSpareBedroom]

OK. Here's your advice: You are NOT going to install styrofoam in your house. Do you understand?

[Dave]

Why is styfoam so bad? A lot (read most) of moulding are made of styrofoam. Same goes for a lot of ceiling tiles and decoration.

[yourname]

I will not visit your family in the burn unit, although it is unlikely you would live through even the most minor fire. Envision melting styrofoam dripping onto exposed flesh.........kewl

Dave wrote:

[JoeSpareBedroom]

Mind if I ask how old you are? I'm wondering how you couldn't know that styrofoam produces toxic fumes when it burns.

I'll ask you one more time: When you consulted your local building code, what did you find out?

[HeyBub]

Styrofoam (brand name of polystyrene) is often used as a residential insulation material.

Any reasonable amount of space should be sufficient (say, 1") or the lighting cans designed for the purpose.

But, as you said, Halogen bulbs are hot. Plus expensive to buy and run. I'd consider CFL.

[Edwin Pawlowski]

Actually, not it doesn't. Other foam may, but Styrofoam is styrene plastic and when it burns, produces soot (a lot of it), water, carbon dioxide) About the same as burning fuel oil. Properly covered, it is useful for insulation and even for Insulating Concrete Forms

as an example.

In any case, it should be covered with drywall. This is a poor application being suggested by the OP.