Loft Insulation- Foam spray or conventional ?

[Retiredandhappyhere]

Has anyone experience of spray foam loft insulation, combined with a ventilator?

How does it compare to conventional loft insulation for cooling capabilities?

I understand that the cost will be about five times higher, but as I have suspended ceilings with many spotlights and limited access, spraying will be simpler and easier to install. The supplier claims that it also waterproofs the roof as well as being a very effective heat reducer.

Any advice will be welcome.

[Rimmer]

Moved to DIY Forum

[h90]

mentioned in a other topic once is that with the foam on it, also the heat can't go out in the night and an fan additionally would be good.

I don't know if true or not, just writing what I read a while ago.

[Naam]

The supplier claims that it also waterproofs the roof as well as being a very effective heat reducer.

suppliers claim a lot. spraying the roof tiles is quite inefficient. you get best insulation efficiency by spraying the foam on the suspended ceilings. expert companies exclude built-in lights. if access is difficult the spraying is done from the outside by temporarily removing roof tiles.

not cheap, cost for 5cm foam thickness ~400-500 Baht per m²; but then you have the "Rolls" of insulation. ventilating the loft/attic is a must whatever you decide.

Edited May 20, 2014 by Naam

[Sheryl]

mentioned in a other topic once is that with the foam on it, also the heat can't go out in the night and an fan additionally would be good.

I don't know if true or not, just writing what I read a while ago.

This has confused/baffled me for some time too.

Heat rises, and to my understanding the window vents up in the loft area are there t help let it out (there is also some space between the roof tiles which can do that.)

Surely sealing all that up would keep heat in?

Or is it assumed that one runs serious a/c 24/7???

[Naam]

mentioned in a other topic once is that with the foam on it, also the heat can't go out in the night and an fan additionally would be good.

I don't know if true or not, just writing what I read a while ago.

This has confused/baffled me for some time too.

Heat rises, and to my understanding the window vents up in the loft area are there t help let it out (there is also some space between the roof tiles which can do that.)

Surely sealing all that up would keep heat in?

Or is it assumed that one runs serious a/c 24/7???

what are "window vents" Sheryl?

[Langsuan Man]

I have heard the term "window" vents used for these vents under the roof under the eaves. Why they are called that is a mystery of Thai to English translation

[Naam]

I have heard the term "window" vents used for these vents under the roof under the eaves. Why they are called that is a mystery of Thai to English translation

vents.png

these vents are "intakes" but have zero function if the attic/loft does not have an "outlet" for the hot air.

[farang000999]

why did they put them all in the same place like that? why don't they build thai houses with soffits in the fascia as is common in the USA?

[Naam]

why did they put them all in the same place like that? why don't they build thai houses with soffits in the fascia as is common in the USA?

that's how most of the Thai homes i know are built. the problem is to find ridge vents in Thailand which are the mandatory soffit partners.

the reason must be that ridge vents are difficult to install on roofs with concrete tiles, especially because the tiles which cover the ridge are fixed with mortar.

U.S. roofs usually plywood and shingles, installation a breeze.

[Naam]

I have heard the term "window" vents used for these vents under the roof under the eaves. Why they are called that is a mystery of Thai to English translation

vents.png

these vents are "intakes" but have zero function if the attic/loft does not have an "outlet" for the hot air.

i forget to add that the openings are too tiny for an efficient air-flow.

[lopburi3]

what are "window vents" Sheryl?

Suspect in reference to opening downstairs windows during evening cooling hours and using attic fan to draw air throughout house and exit from the attic area as is often done in the US?

[malcolminthemiddle]

CPAC Monier do (or did) a Zephry Roof Vent Tile.