Insulation

[Jim Benante]

I am making my covered porch part of the home and want to insulate it. I will be able to have vaulted ceilings, but there are only 2X6 roof beams so what is the best way to get a high R value on vaulted ceilings with 2X6 beams.

What was once a deck and porch will now be foyer and storage area below. These are older pics as I now have completed my concrete work below and framing. After I enclose this area nd install the windows and door I will build an ipe deck to and steps to get to the entrance. There used to be a deck and stairs, but they were falling apart so I tore them down and I began my journey into this addition. I need to shoot a pic today when I get out there to work on it.

The knotty pine panelled ceiling has been removed and I'd rather have the area vaulted rather than put up a another low ceiling so any help with how to insulate would be appreciated.

Thanks,

Jim

[Jim Becker]

Closed cell spray foam will give you the highest R-value per inch. In a 2x6 bay, you can get nearly R38 with this material. Not DIY, however. Before you do your porch conversion, however, be sure it has proper footings, etc., so that you don't have code issues.

[Jim Benante]

be sure it has proper footings, etc., so that you don't have code issues.

Jim,

I poured a footer and a 14 inch wall to meet the code requirements. I also poured a slab. I made sure to keep the addition foundation seperated from the house foundation with expansion joint material.

As soon as my camera batteries charge I'll take a few more shots to show the progress and dilemmas I face with insultation.

Here is a shot of the footer with the framing for the 14 inch wall set up for the pour. I used 1/2 rebar and the handy spacers which made the job quite easy. The slab pouring was not quite so esy as I went at it alone and was super stressed on hot summer day all. All for not as the concrete did not cure as fast as I would have expected.

Jim

[Jim Becker]

Good deal, Jim. I only mentioned the footer, etc., as I've seen some folks de-railed on similar projects when they didn't realize it was an issue...including a good friend of mine a number of years ago. It was really costly to rectify... ;)

[Ben Grunow]

Jim is right about the foam but it is spendy. If you are doing this yourself you could add some 2x6's under the existing ones (put some small strips of pplywood along side to tie them together) and insulate with stadard fiberglass insulation. Just be sure to maintain some ventilation under the roof sheathing (use prop-a-vent (sp?) styrofoam things that leave 1 1/2" air space below the sheathing, cheap) and install a vent strip at the eave if there is not one already.

[Jim Benante]

Ok- Here are the more updated shots. I have one wall to complete. Hopefuly by the end of the day it will be. I had to cut away some of the gutter and will need to recap it later today.

Jim- When using the closed foam spray in insulation do you still maintain air space?


Ben- I had thought about sistering some 2X10's. I hadn't thought about using plywood to do it.

I need to make up my mind quick as I don't want any critters to find a home in my walls.


Can you use foam over the joists and then drywall over the foam? Seems like a good options except I guess you would need really long screws to penetrate the drywall, foam, and into the joists.

Jim

[Jim Becker]

Spray foam can go right to the roof underlayment.

You did hit on an alternative, however. If you put in vent channels up the bays, you can use high density R-19 bats and then overlay rigid foam on top of the joists for additional insulation. Furing is then put across the joists on top of the rigid and then the drywall is applied. You can probably get close to an R-28 or R-30 that way, depending on the thickness of the rigid insulation.

[Jim Benante]

If you put in vent channels up the bays,

Can you explain vent channels to me? I am not sure what you mean. I also do not know what Ben was refering to when he said


under the roof sheathing (use prop-a-vent (sp?) styrofoam things that leave 1 1/2" air space below the sheathing, cheap)

This is all new to me so I am trying to learn all I can so I make wise decisions.

[Jim O'Dell]

Jim, they are styrofoam or plastic panels about 4' long in the shape of a shallow W. They have a flat flange on the outside edges and in the middle to staple to the underside of the roof sheathing. This gives a guearanteed air space between the roof sheathing and the insulation, at the eaves especially, so that you don't get the ice dams built up in the winter, and the air has a way to move from your soffit vents to your ridge vents or turbines to expel heat in the summer and moisture all year long. Home Depot has them for sure. they are pink in color and my HD has them by the sheets of rigid foam board an aisle away from the roofing materials. If you need a visual, let me know and I'll go shoot a picture of some I have installed in the shop. Hope this helps! Jim.

[Jeff Wright]

You may want to look into Thermax rigid foam insulation, a Dow product. Its 2" thick has an R13 value. I called the Dow tech desk and they said it can be doubled up to increase the value to R26. It also comes with a bright white side to it to help make the room/shop lighter. I plan to use it to insulate my 2-car garage shop by cutting it and lying it between my 2x6 rafters and then using their tube sealant to seal between the cut pieces and my rafters. My garage has 465 square feet of roof area and it will cost me about $700 for the panels if I go with one layer of 2" foam. Panels come in 4x8 pieces and various thicknesses up to 2". They are closed cell foam panels. My problem is I have no roof vents and do not want to install them in my new $18K tile roof here in Florida. So installing bat-type insulation (which would require circulation between it and the subroofing surface) is not an option for me. Here is the web link to Thermax:

http://www.dow.com/styrofoam/na/thermax/products/thermax_white.htm

[Jim Becker]

Jeff, don't worry about the "white" surface. The insulation must be covered to meet fire code...especially foam which is very flammable. Foil-faced FG is one exception to that. Yea, a lot of folks leave it exposed in shops, but...

[Jeff Wright]

Jim,

Dow technical department disagrees with you about the need for covering their Thermax rigid insulation. Of course, one's local building code inspector is the one who holds the decisive answer!

From the Dow website:

When you’re building or remodeling, start off on the right foot … with THERMAX™ insulation in basements and closed crawl spaces. THERMAX Sheathing and THERMAX White Finish (WF) insulation products deliver outstanding thermal performance, moisture resistance and fire performance that make your homes more energy-efficient from the ground up. In basements, THERMAX Sheathing, with an aluminum foil facer, and THERMAX White Finish, with a white embossed facer, help you make your space more comfortable and more attractive. Because they can be left exposed to the interior without a thermal barrier, THERMAX Sheathing and THERMAX White Finish create a semi-finished or finished appearance in one easy installation step.
THERMAX Sheathing is also highly effective as an insulation in closed, conditioned crawl spaces, an assembly gaining popularity for its energy and moisture control.
Energy Efficiency With an R-value of 6.5 at 1", THERMAX insulation products are among the most energy efficient of all rigid foam insulations. And the unique formulation ensures high performance over the long term. THERMAX insulations are created through an exclusive free-rise process. The combination of closed-cell core foam and sturdy facers produces boards that deliver outstanding insulation, dimensional stability and moisture resistance.
Fire Rating

THERMAX insulation products can be installed exposed to the interior, without a thermal barrier.** That translates to savings in time and materials. THERMAX insulation is Factory Mutual approved as “Wall-Ceiling Construction, FM Approvals Standard FM 4880, Metal-Faced – Class 1 Fire Rated to a Max. 30 ft. High.” Homeowners may qualify for reduced insurance premiums.†
Easy-to-handle THERMAX insulations require no special tools or materials for installation. Simply use a utility knife and a straight edge to cut the boards to size. Then adhere directly to basement walls with an approved adhesive. In closed crawl spaces, THERMAX Sheathing is installed using powder driven nails. For extra protection against air and moisture, and a more finished appearance, use one of the joint closure systems available from Dow, or tape seams with THERMAX white foil tape or aluminum foil tape.
More Options, More Applications

Add more value to garages and pole barns with THERMAX Heavy Duty and THERMAX Light Duty insulations. Sturdy acryliccoated aluminum facers deliver high insulating value plus durability and pressure-washability.

[Jim Becker]

Thanks, Jeff. That apparently is a newer product that they have deal with the code issues for exposure. Good to know!

[Jim Benante]

I did a quick web search and have found a number of spray foam kit suppliers. Here are two

http://www.tigerfoam.com/

http://www.foampower.com/

Jim you saud it is not a DIY. Why?

Does anyone have any experience spraying there own closed cell insulation. I spoke with one company and he even suggested for my walls spraying just 1 inch then puttin in R-13 fiberglass insulation.

I only have 60 sq ft of ceiling and 60 sq ft. of under floor and about 100 sq ft of walls.

Is there any reason I can't do this myself? I am trying to get a few quotes for having the service done for me just to compare costs.

[Jim Becker]

When I was in the insulation business, we used "portable" product like shown in the links for sealing work and small areas, but never for expansive spaces.

I suppose you could use it in your small space. If you do, buy a few cheap Tyvek body suits with head coverings, nitrile gloves and wear really old, disposable shoes. You do NOT want to get this stuff on your skin. Needless to say, eye protection and a respirator are also necessary. The trick will be to adequately judge how much you need. 'Nice thing is, you can put it right on the underside of the roof deck...something you cannot do with fiberglas. That requires venting.

I don't buy the "install one inch" and then do R13 unless you're doing 2"x6" walls. If it's 2"x4" studs, R13 glass requires the full cavity.

For reference, the R19 (3") I had put under our great room last year came out to about $2.65 a square ft installed in a crawl space. We are doing our whole addition (full envelope) with the closed cell foam.

[Ben Grunow]

THere is a foil faced paper that comes on a roll called EFX paper that can be stapled over the paper face on insulation to get it to pass the fire code (reduce flame spread rating) but I would nto want to rely on that in the shop either. Solid plywood or drywall.

[Jim Benante]

When spraying this foam in what do you do about electric outlets, wires, light fixtures, etc? Just put them in place and spray away? Of course you would have to cover any outlet boxes somehow.

I was thingking about canned lights in the cathedrals. Can you do this with the foam?

[Jim Becker]

Jim, since your insulation goes in after your rough electrical, plumbing, HVAC and framing inspections are complete, you'll need to insure you don't get the stuff in your boxes since they will be in the walls. This is one of the challenges for a DIY job...there is a learning curve relative to "knowing" how much to spray, etc.

I don't know the answer to your question about the cans...'probably depends on the fixtures, but you may need to box around them. Ask the insulation suppliers to clarify. Regardless, consider LV lighting. Smaller fixtures and they will fit in those 2"x6" bays just fine.