Topic 'Re: Spray Foam or Batts' in forum 'Home Improvement' - dslreports.com

Re: Spray Foam or Batts

Mon, 04 Feb 2013 06:05:21 EDT

anon posted : Before you make that purchase visit the EPA website about spray polyurethane foam. If you don't know what to prepare for this could be the most expensive mistake you could ever make. Also read what the CDC has to say about it. These products placed in untrained hands could place you in the ER for pulmonary distress.

Re: Spray Foam or Batts

Thu, 31 Jan 2013 14:34:53 EDT

LazMan posted : Agreed, the building science methods are excellent... I was just simplifying. Vapor barrier to the warm side; whichever that may be... ;)

Re: Spray Foam or Batts

Thu, 31 Jan 2013 07:27:20 EDT

doechsli posted : Lots of great ideas here guys.....I appreciate it.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 23:17:14 EDT

MaynardKrebs posted :

said by LazMan:

Vapor barrier placement; if one is required, is dictated by temperature - it goes to the warm side of the wall - basically, if you spend more time heating, barrier goes on the inside; if you spend more time cooling, it goes to the outside...

Holmes on Homes was filmed around Toronto, Ontario, Canada... Hence vapor barrier on the inside.

It depends on where the dewpoint is inside the wall cavity, which is a function of the temperature differences inside to outside, and the type of insulation & thickness. Foam sprayed in a wall cavity up against the sheathing in sufficient thickness will change the dew point in the wall to the point where water can't condense. You then fill the remainder of the cavity with batt insulation and drywall right over the batts without a poly vapour barrier. This gives the wall assembly what it needs - the ability to 'dry' to one side - in this case the interior.

A former classmate of mine is the principal @ www.buildingscience.com You can read about insulation there. Joe is one of, if not THE leading expert on this in North America.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 23:08:02 EDT

MaynardKrebs posted :

said by Draiman:

Another option is add a 2x2 or another 2x4 onto the existing 2x4 thus extending it to add more fiberglass insulation. Yet another option is run a ton of empty conduit in the wall before you foam. Personally I'd extended the framing with another 2x4 to give you 8" of space then fiberglass with facing towards the inside and drywall over that. Cheap, simple, and effective.

Strapping a 2x2 over the existing 2x4 is a good idea, but what I'd do is spray 2" of 2lb foam into the wall cavity first. This create a vapor barrier at the exterior wall sheathing - 2" of 2b. IS a real vapor barrier according to all tests done by manufacturers & testing labs. Then install the batt insulation over that. This gives you about R26-28 in a 6" nominal wall and he ability to easily fish wires at a later time.

Do not install a poly vapor barrier over the batt insulation in this case - there should be one and only one vapor barrier in a wall, and that is provided by the 2" of foam sprayed against the exterior sheathing.

You can read more about 'hybrid' insulation like this at www.buildingscience.com

Re: Spray Foam or Batts

Wed, 30 Jan 2013 22:59:57 EDT

MaynardKrebs posted : You can try this trick in doing your walls:
a) measure the height of the ceiling - let's assume 96"
b) measure the height of the baseboard you'll be installing. Let's assume 5"

c) Cut the drywall to 92" tall overall
d) install the drywall snug to the ceiling (you'll be 4" shy of the floor)
e) rip a sheet of 1/2" plywood into 4" wide strips
f) screw the plywood strips to the studs below the lower end of the drywall
g) attach the baseboard to the drywall (it will overlap the drywall)

Now if you ever want easy access to ALL stud cavities, just pop the baseboard off and unscrew the plywood.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 20:34:17 EDT

alkizmo posted : Maybe I read too fast so I missed someone suggesting the follow: XPS foam boards sealed with a little bit of spray foam. Much cheaper than spray foaming everything.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 20:06:03 EDT

LazMan posted : Vapor barrier placement; if one is required, is dictated by temperature - it goes to the warm side of the wall - basically, if you spend more time heating, barrier goes on the inside; if you spend more time cooling, it goes to the outside...

Holmes on Homes was filmed around Toronto, Ontario, Canada... Hence vapor barrier on the inside.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 19:53:22 EDT

anon posted : Why not use what you want and then just strap the 2x4s.
The strapping is cheap[1x3]and allows room for running wires as the strapping is applied across the 2x4s.It also allows a bit af breathing space[healthier]and also noise reduction.
Also you might want to put a plastic[6mil] vapor barrier on the outside of the insulation instead of inside.Not the norm but Mike Holmes endorses it.[from Holmes on Holmes]He endorses it because it truly is a vapor barrier for your inside as well as your choice of insulation,whereas the normal way only keeps moisture from the drywall leaving any and all insulation susceptable to leaks.
Just a thought.I have done it both ways and keep in mind that spray foam is nearly impossible to remove intirely.
One can also run some abs/pvc tube or conduit tube for future running of wires when spray foam has been applied.
Good luck!!

Re: Spray Foam or Batts

Wed, 30 Jan 2013 19:49:11 EDT

panth1 posted : Spray foam will give you the better R value per inch but it will cost more.

If you are worried about cabling, fur the walls out to 2x6's or 2x8's and only fill the cavities partially with spray foam. Leave a little space between the foam and drywall for future cabling.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 19:28:00 EDT

grobinette posted : Whoa, settle down guys. Don't get yourselves all bent out of shape over a difference of opinion.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 18:50:59 EDT

robbin posted :

said by doechsli:

I think foam is the best insulator per inch but once insulated, you can't ever fish a wire again in case the need arises.

It doesn't have to be one or the other. Many people spray one inch of foam and then use fiberglass. That adds R-value as well as seals the house to air infiltration while still allowing the potential of pulling new wires. However, in my experience, you don't pull wires in exterior walls. You almost always have to cut the sheetrock as there is no attic access to drill through the top plates. Worst case with a foam filled wall is you have to do some foam carving to install the new wire. Not that big of a deal.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 17:47:04 EDT

VioletVenom posted : If the shoe fits, wear it. When you come across as pompous, as you still are, don't act so indignant when you get called out for it. I'm sure the OP is a big boy and can read through all the comments and make an educated decision by what everybody has posted. For some people cost is a major factor. I believe others have covered those "other factors" and will continue to do so. To single out my post and claim it is "totally worthless". Well played. :uhh:

Re: Spray Foam or Batts

Wed, 30 Jan 2013 16:59:18 EDT

robbin posted :

said by VioletVenom:

You can pull those knickers out of your bum now.

Instead of throwing insults why not behave in a civil manner. Your cost comparison was missing in many details. This is not just about dollars. Foam accomplishes a number of things which batts do not including more R-value in the available space as well as the vapor issue. There are others as previous posters have indicated. Just looking at the dollars per cubic foot of insulation without regard to any other factors is totally worthless!

Re: Spray Foam or Batts

Wed, 30 Jan 2013 16:53:53 EDT

VioletVenom posted : You're right, OP never gave dimensions. I was giving a cost comparison for X amount of wall space, I wasn't trying to give him a job estimate. You can pull those knickers out of your bum now.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 16:50:50 EDT

ArgMeMatey posted :

said by LazMan:

Bonus with sprayfoam; if you go with close cell foam of sufficient dept (1.75-2" I believe) it also acts as a vapor barrier...

Even some open cell foam qualifies as a vapor barrier in Wisconsin. Maybe not all of them but the manufacturer will give you a copy of a certificate from the state if they have gone through the process.

I have open cell and am very happy with it, although if I did it again I'd also get bids from some closed cell contractors. The foam draft sealing is far superior. A few Januaries ago, I took a look at some FLIR images of foam vs. blown-in and batts. The difference was night and day. Batts looked more like the no-insulation images.
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Re: Spray Foam or Batts

Wed, 30 Jan 2013 16:47:51 EDT

R4M0N posted :

said by Goober:

said by John97:

A couple of options to consider.. You could future-proof the room by installing extra AC outlets, coax drops, ethernet drops, phone jacks, etc. Or, while you have everything open put in some conduit runs with outlet boxes so you can fish cable later. Just put blank faceplates on the outlet boxes to close things up.

I agree. 28 Cat 6 and 12 RG 6 coax in each room should do it.

LOL... Nothing like a good inside joke to make me LOL at the end of the day.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 16:43:09 EDT

Draiman posted : Another option is add a 2x2 or another 2x4 onto the existing 2x4 thus extending it to add more fiberglass insulation. Yet another option is run a ton of empty conduit in the wall before you foam. Personally I'd extended the framing with another 2x4 to give you 8" of space then fiberglass with facing towards the inside and drywall over that. Cheap, simple, and effective.
--
IF YOU FIND ANY MISTAKES IN MY WORK...Please consider that they are there for a purpose. I try to please everyone and there is always someone looking for mistakes!

Re: Spray Foam or Batts

Wed, 30 Jan 2013 15:29:34 EDT

tschmidt posted :

said by LazMan:

the labour savings in not having to hang and seal the poly vapor barrier helps offset the increased cost of the spray foam.

Not to mention that even a pinhole in the poly vapor barrier can transport a huge amount of water vapor into the insulation.

/tom

Re: Spray Foam or Batts

Wed, 30 Jan 2013 15:20:37 EDT

LazMan posted : Bonus with sprayfoam; if you go with close cell foam of sufficient dept (1.75-2" I believe) it also acts as a vapor barrier...

I don't know if that's a requirement where you're at, but up here in Canada, it is - and the labour savings in not having to hang and seal the poly vapor barrier helps offset the increased cost of the spray foam...

As for DIY foam kits, they are out there, Tiger Foam (»www.tigerfoam.com/) is the one I'm most familiar with - comes in two tanks, with a set of hoses and applicator - works well, when you get the hang of it - but it's not cheap... If you have a substantial amount of foaming to do, it may be cost-neutral or even a better value, to bring in pro's. Worth a call, anyways...

Re: Spray Foam or Batts

Wed, 30 Jan 2013 14:56:00 EDT

robbin posted :

said by VioletVenom:

Ok, I stand corrected, there is a DIY foam kit. Someone sent me a link to this.
»www.sprayfoamdirect.com/home-own···ications

So, it is available but up front cost is still expensive. Using their estimator, I estimated 240 SF (3x8x10). Came out to $931 for spray foam vs ~$140 for R-19 fiberglass.

There are MANY DIY foam kits. Not sure how you estimated 240 SF as the OP didn't give any dimensions other than

said by doechsli:

The framing is 2x4 so not a huge amount of space.

which would rule out R-19 batts. On the other hand, foam is around R-7 per inch, so the 3.5" thick wall cavity would be R-24.5 if filled with foam versus R-13 with batts.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 14:52:23 EDT

Goober posted : I think it's cheaper if you get it locally. Ours wasn't nearly that expensive.
--
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Re: Spray Foam or Batts

Wed, 30 Jan 2013 14:47:43 EDT

Draiman posted : Here's an old thread on DIY spray foam.
»DIY Spray Foam Kit Review

Re: Spray Foam or Batts

Wed, 30 Jan 2013 14:32:15 EDT

garys_2k posted : Wow, yeah, that IS expensive!

In any case, regarding future wiring, if you'd be running new wires in from the top you could glue a raceway like this »www.cableorganizer.com/surface-r···ards.htm behind the drywall, with a length centered in every second or third stud cavity. As long as you decided to put your new drop right between the studs you'd hit the open side of the raceway.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 14:24:05 EDT

Goober posted : I believe even the local hardware stores carry it. Our contractor got it through a big box store I thought. He used the stuff for our sunroom outside walls. It is expensive, but I think it's worth it.
--
"You lie!" Talk about an understatement, Joe.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 14:20:06 EDT

VioletVenom posted : Ok, I stand corrected, there is a DIY foam kit. Someone sent me a link to this.
»www.sprayfoamdirect.com/home-own···ications

So, it is available but up front cost is still expensive. Using their estimator, I estimated 240 SF (3x8x10). Came out to $931 for spray foam vs ~$140 for R-19 fiberglass.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 14:14:21 EDT

BillRoland posted :

said by Goober:

said by John97:

I agree. 28 Cat 6 and 12 RG 6 coax in each room should do it.

That made me LOL.
--
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Beyond AM. Beyond FM. (((XM)))

Re: Spray Foam or Batts

Wed, 30 Jan 2013 14:13:31 EDT

robbin posted : Spray foam is more expensive but it has a higher r value per inch. There is no reason that foam is not DIY. There are a number of companies which specialize in spray foam kits.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 14:11:13 EDT

H_T_R_N posted : I always use foam where I can.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 13:58:55 EDT

VioletVenom posted : The difference between the two insulations is going to be DIY opposed to hiring an insulator. Even on a smaller wall area doing spray foam out of a can would be expensive compared to batts.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 13:31:22 EDT

Goober posted :

said by John97:

I agree. 28 Cat 6 and 12 RG 6 coax in each room should do it.
--
"You lie!" Talk about an understatement, Joe.

Re: Spray Foam or Batts

Wed, 30 Jan 2013 13:04:40 EDT

John97 posted : A couple of options to consider.. You could future-proof the room by installing extra AC outlets, coax drops, ethernet drops, phone jacks, etc. Or, while you have everything open put in some conduit runs with outlet boxes so you can fish cable later. Just put blank faceplates on the outlet boxes to close things up.
--
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Re: Spray Foam or Batts

Wed, 30 Jan 2013 12:57:00 EDT

tschmidt posted : We have a timber framed house with stressed skin panels for roof and walls. You are correct with foam fishing cables through the wall can be a challenge. The advantage is solid insulation is much better insulation and moisture control then fiberglass batts.

If you concerned about later access have you though about using fiberglass in the stud cavity and solid foam panels on the inside between the studs and drywall? That accomplishes several things it moves to dew point to the foam rather then fiberglass and minimizes moisture infiltration to the stud cavity.

/tom

Spray Foam or Batts

Wed, 30 Jan 2013 12:46:31 EDT

doechsli posted : I'm planning a summer project to rip down paneling in a room and replace it with drywall (paneling nailed to studs). While I'm in there I want to insulate the walls as three of them are outside walls. The framing is 2x4 so not a huge amount of space. I've asked several tradesmen about spray foam vs. batts and gotten a myriad of answers. I think foam is the best insulator per inch but once insulated, you can't ever fish a wire again in case the need arises. Any experiences to share?