What is the best exterior wall insulation

[h-town humidity]

I was wondering if any of you had opinions on the best wall insulation. I am building a new home in Houston, Texas, and the standard wall insluation is R-13 unfaced batts in 2x4 walls and R-19 on exterior 2x6 walls. The standard insulation in the attic (two story home) is R-30.

I am going to upgrade to R-38 blown in for the attic, and have been given a quote for Ownes Pro-Pink blown in for the exterior walls. Have any of you had experience with this stuff and what are your thougts versus cost as it is 2-3 times the cost.

Also, they are using cellulose spray for sound control on some of the ceilings and R-11 owens-corning sound batts around some interior walls. Why not just use spray on substances or other?

Essentially, I am in need of help for the best reccomendation on insulation for the house. We went with three Trane 14 SEER, 80% variable furnace systems with Lennox media filters in the house and want to maintain as much energy efficency as is worth the cost. Thank you for your help.

[platchford]

I went with spray-in foam insulation for my home by an Icynene dealer. It deadens sound tremendously, seals out nearly all air infiltration through the walls (not that this should be a problem with new construction), it doesn't settle over time and it does not readily absorb water if you were to have some sort of leak. You'll pay more for it but in my opinion it is well worth it. One of the problems with fiberglass and many other insulations is if you have air infiltration through the wall then the R value of the insulation is almost completely negated.

[Daltex]

I agree with using the spray foam insulation. Increased R and air tight! If cost is too high then maybe just the south and west walls with fiberglass on north and east. Heat gain will be your biggest expense in Houston.

[brian in mass]

spray foam is the only insulation in my eyes if there is an option.

[firecontrol]

For lower air conditioning loads I put this product on my new home when I built it.

http://www.jm.com/insulation/buildin...foil-faced.pdf

I'm not sure what help it did in the heating months which are long here in wisconsin, but when we have 95° summer days I can cool 1600 sq ft with a 5000 btu window shaker to as low a temperature as the control will go down to.

[platchford]

For lower air conditioning loads I put this product on my new home when I built it.

http://www.jm.com/insulation/buildin...foil-faced.pdf

I'm not sure what help it did in the heating months which are long here in wisconsin, but when we have 95° summer days I can cool 1600 sq ft with a 5000 btu window shaker to as low a temperature as the control will go down to.

Which R value (thickness in this case) did you use? How much did it add to the cost of insulating your home (per sq ft)? I'm only asking because I looked into similar products when rehabbing my house and, honestly, it was basically the same cost to have someone else spray foam as it would have been to have ME insulate with fiberglass and exterior foam sheeting. To top it off, the spray foam will still fill gaps and eliminate more air infiltration than the foam sheeting. Regardless, it still seems foam of one type or another is the winner.

[mlo1]

Generically commenting...cellulose dense fill or wet blown. Like most everything, a quality install is also key. You happen to live near Payless insulation. Larry is a great wealth of knowledge and knows your climate. Maybe give him a ring.

[rtucker]

I insulated a home last summer with B.I.B. insulation. It stands for Blown In Blanket. They cover the studs with a thin cloth, much like on the back of box springs. Then the blow in loose fill insulation. The product has a lifetime manufacturers warranty from settling. It can actually be packed it a little tighter and raise your R-value somewhat. That is still a big debate with all products. (packing x cost = not much gain in R-value) I have been happy with it and it is better than batts and cheaper than foam. They have a web site. Do a search.
RT

[Daltex]

Remember also that the wall heat loss is much less than the ceiling loss. I don't think I would pay for the wall foam in a new install unless the attic was also foamed (due to the main benifit of decreasing air infiltration).

[teddy bear]

Air tight is good but what about mechanical fresh air ventilation? Regards TB

[platchford]

I insulated a home last summer with B.I.B. insulation. It stands for Blown In Blanket. They cover the studs with a thin cloth, much like on the back of box springs. Then the blow in loose fill insulation. The product has a lifetime manufacturers warranty from settling. It can actually be packed it a little tighter and raise your R-value somewhat. That is still a big debate with all products. (packing x cost = not much gain in R-value) I have been happy with it and it is better than batts and cheaper than foam. They have a web site. Do a search.
RT

In general, how would you really ever know if the product settled in the wall or not? Also, packing it tighter to increase R value doesn't sound right... makes as much sense as packing fiberglass tighter which would decrease R value... how does this work?

Remember also that the wall heat loss is much less than the ceiling loss. I don't think I would pay for the wall foam in a new install unless the attic was also foamed (due to the main benefit of decreasing air infiltration).

Honestly, why would you not foam the attic if you are foaming the rest of the house? At a minimum do 4" of foam in the attic followed by several more inches of fiberglass in order to achieve the R value you need if you don't want to do all foam. Also, the foam I mentioned is open-cell... if you really want some R value choose a closed-cell and the R value per inch nearly doubles.

Air tight is good but what about mechanical fresh air ventilation? Regards TB

Very true. In my opinion I'd rather have a mechanical fresh air intake that I can filter rather than depending on the loose construction of my home. Also, mechanical fresh air ventilation gives you the opportunity to utilize any number of systems that recover some of the heat from the stale exhaust air and apply it to the incoming fresh air.

[Daltex]

Honestly, why would you not foam the attic if you are foaming the rest of the house? At a minimum do 4" of foam in the attic followed by several more inches of fiberglass in order to achieve the R value you need if you don't want to do all foam. Also, the foam I mentioned is open-cell... if you really want some R value choose a closed-cell and the R value per inch nearly doubles.

I already said I'd foam the attic. Most of the foam insulation in my area is closed cell. The attic foam is on the inside of the decking, not on the attic floor, so you don't add batting.

[platchford]

I already said I'd foam the attic. Most of the foam insulation in my area is closed cell. The attic foam is on the inside of the decking, not on the attic floor, so you don't add batting.

Sorry, my point was more directed as a "why wouldn't someone foam the attic" rather than a why wouldn't you foam the attic... my bad. As for foaming the decking, that is definitely the better way to go. I was speaking speaking from more of an installation cost standpoint being that there is less surface area on the floor than within the decking.