Foam Board Insulation

[rocketmankabin1]

Does anybody know where I can purchase foam board insulation where I can cut it to size and fit it into wall panels?  I need 2.5 to 3 inch thick boards.  I built an apartment addition to our house with metal framing and want to insulate the wall panels by myself.  I've seen Tyvek here on outside of 7/11 as being built but probably want something thicker.  This Dow Insulation board is 2" thick.

 

 

 

[manfredtillmann]

the foil shown in your photos is what is called a 'breather sheet'. it prevents moisture penetrating through the outer skin of you building onto the inside. in order for it to work ok you need weep holes in the outer building skin and i have never seen any on any building here so far.

the 'foam board insulation' you mention, but not provide an example for,  is that styro foam? while it might be a good insulator, it is also a sure - fire recipe for mould!  a successful insulation requires ventilation. the heat built up on the outside needs to be able to rise and transfer condensation with it at the same time. a simple top vented air gap between outer and inner skin will do a much better job than filling the wall space with styro foam.

thai building practices do not live up to universal building standards, they have not even met the 60's.

 

[rocketmankabin1]

I don't think it was breether sheet that I wanted then.  I guess the big question is how to best insulate this wall so the air con won't work so hard.  Standard rolled insulation?

[manfredtillmann]

spent 80% of your money on roof insulation, i can see no breather membrane there so you already set yourself up for problems. this is where most your heat comes in and goes out and where, in wet climates, the majority of condensation occurs.

a single m2 of roofing can generate 80 watts of heating power! try to combat that with your a/c.

 

for the walls - and the roof, breather sheet to the outside and an open cell insulation (glass wool, rock wool) between breather sheet and interior lining. nothing solid like styro foam as it inhibits evaporation.

check out a few european websites for pointers.

cheers

mft

[Mrjlh]

Check Global Home or Do Home and even Home Pro for fiberglass rolls. Place moisture barrier to the outside. Alum tape only the sides and leave top and bottom unsealed to allow moisture to escape.

[rocketmankabin1]

manfredtillman, what is a breather membrane? 

Super Member, what is the moisture barrier?  I have no clue in building so I need a little help here.  Looks like the Thais building this don't have a clue either.  They didn't even want to put rolled insulation in the walls.

[ClutchClark]

Any chance you guys can provide photos of what you describe? 

[rocketmankabin1]

CluthClark,

The photo of the wall, roof is there.

 

[ClutchClark]

3 minutes ago, rocketmankabin1 said:

CluthClark,

The photo of the wall, roof is there.

 

 

Thanks its just that some of the descriptions you use sound more European than American. 

I don't quite understand some of the posts.

 

I understand the explanation for not using rigid foam due to moisture build-up and mold. 

I live in a dry climate stateside and this is interesting to me how its done correctly in LOS.

 

cheers

[rocketmankabin1]

I don't know how to do it correctly in the LOS.  That's the problem.  LOL   I've never built a house or addition.  The house this addition is connected to is solid concrete and only has that silver 1/4 foam insulation stuck to the metal sheet roof.  Doubt if it helps much with cooling.

 

 

[Lite Beer]

This really is the wrong forum

[Don Chance]

In cold climates we put the vapour barrier on the inside but in hot climates you the VB put on the outside as was mentioned.  The idea is that outside is hot humid air while inside with you A/C will be dry so any condensation that may form inside the wall will be able to dry inwards.

A VB will help keep the humid air out and reduce your cool cost.

Wood is good because it absorbs moisture or dry wall.  I've heard about hotels having problems due to vinyl wall paper which created a VB and then no way to dry out and then mold.

Foam board is a good choice because it holds air too, you can cut it was sharp blade and seal it in their with some caulking. Spray foam would be ideal.  The foam acts like a VB. 2-4" would be ideal and keep in mind to seal it airtight.

Edited September 5, 2016 by Don Chance

[manfredtillmann]

11 hours ago, rocketmankabin1 said:

manfredtillman, what is a breather membrane? 

Super Member, what is the moisture barrier?  I have no clue in building so I need a little help here.  Looks like the Thais building this don't have a clue either.  They didn't even want to put rolled insulation in the walls.

sorry for the late reply. it is a perforated foil, also know as sarking or foil insulation etc. it is simply a membrane with little insulation properties to prevent moisture and insects from entering the wall cavity between your outer cladding and your inner lining. it prevents your timber wall frame from rot and is a must have in board - cladded building like the one shown in you photo. it is too late to fit it now.

i would still strongly suggest to use rock / glass wool insulation in the ceiling space. you can staple string across the ceiling joists and slide the insulation in, it will stay there until the plasterer puts the sheets up. only have a picture of a gable roof handy but you'll get the idea. r2.5 or better and DO NOT USE organic material such as wool or cotton based stuff.

 

no, thai building standards are at the same level as german or australian standards were in 1960. do not hesitate to tell your builders what you want, it does not matter what they think of you. you have to live in this building, they just collect their money and walk away to the next 3rd rate job.

Edited September 6, 2016 by manfredtillmann
spelling

[Kwasaki]

I'm getting a bit lost here,  l take it OP's construction picture is ID 3 and wall elevations and roof structure is steel, IMO he could use either foam or fiberglass as long as is has some venting but foam is self supporting so better for walls.

Can't really see roof structure he may have a liner in use already if not while boarding the ceiling he can feed fiberglass into cavity as he progresses.

 

If you ask about you can get everything you need, there's as said the best IMO  Global House,  and also Homemart's, Home Pro etc etc.