Q&A Forums

Old Craftsman style vaulted ceilings? Post New Topic | Post Reply

Author Comments
Cory Lubbert
Posted: Jan 23, 2008 02:04 PM
Old Craftsman style vaulted ceilings?
I have an old, craftsman style (mission-arts and crafts) home, that on the 2nd story has sloped ceilings that exactly parallel the roof above the staircase, as well as all of the closets are under the eves with sloped ceilings, and a few of the rooms have a notch at the ceiling of about 2 feet that is sloped, not a large amount of ceiling space in the rooms, but a very large amount over the staircase and in the closets.
Now the only insulation in these ceilings is well some form of 1 inch thick straw mat that is held against the roof with lath on each rafter.
The rafters are 2x4 so there is only 3 1/2 inches of air space between the roof and the plaster ceiling subtract the straw mat and there is only 2.5 and some of that is falling down in the attic so Im guessing it is in the ceiling too. Obviously I am losing a tremendous amount of heat out here in the winter(always melts all the snow and lots of icecicles) and gaining a lot of heat in the summer under this black roof(ceiling is warm to the touch in summer some days).
This is my idea to fix this. Gut the ceiling, above the staircase and in the closets, being careful not to disurbe the rest of the walls and ceilings to prevent more repair then necessary. remove the old straw insulation. Fir up 2 inch strips above the stair case to give me 5 1/2 inch air space, to increse the amount of foam I can put in. Then fill the space completely up with closed cell foam. And Sheetrock over it. I believe this should give me close to an R38 value. Does this sound like a good Idea, is there a better way of doing this? should I leave an air space? Do I need the additional 2 inches or is this overkill? What about Venting under my eves? There is no venting present under my eves now and there is a dormer on the opposite side that could have vents to give venting to the roof, if that would work. There are gabble vents and roof vents now with no soffet vents on the house. What about a radient barrier, if I put a radient film up can I sray the foam then put the radient film on then sheetrock or does the radient film need to be next to the roof deck?
Any expertise would be greatly appreciated.
Thanks
Cory
Cory Lubbert
Posted: Jan 26, 2008 12:25 PM
Anyone??
SprayFoamSupply.com
Posted: Jan 26, 2008 01:24 PM
Cory,

It is difficult to picture the job from your description. You only want to insulate above the stairs and closets? What about the rest of the roof? I think that you should have a local spray foam contractor do a site visit so that he can advise you. Where are you located?

George
Cory Lubbert
Posted: Jan 26, 2008 02:21 PM
I am located in Northern Iowa. The rest of the roof is a standard vented attic space with loose cellulose insulation. I will probably add more there too, but the main problem is the sloped ceilings. Basically, it would be like a house that is a story and a half or story and 3/4 that sloped ceilings in the rooms upstairs. (maybe consider a cape cod style) Those sloped ceilings are mostly just in the closets in my house though and also above the stairwell, and a slight notch at the ceiling in each room. These ceiling/walls have no insulation other than the inch thick straw mat. This home was built in 1920. The rest of the house has been remodled and has had insulation blown in the walls and in the attic, Has all new windows, doors, siding, roof, everything but they never did anything with the insulation in this part of the roof.
I have contacted a contractor but he has not made time to come look at it and give me any ideas or estimates. I plan to do somthing this summer when it warms up a bit, but want some ideas before the time comes. Especially because I want to do all the work as far as the demo and construction, except for the foam, myself. And I feel its always better to do some research before hand than to wish you would have done something easier or better once its all done with.
Edward Brassington
Posted: Jan 30, 2008 12:15 AM
I have done many houses with this style roof. You are on the right track. I would suggest remove all of the sloped ceilings and install 3.5-4 inches of closed cell foam. You don't need to strap the ceiling, yes you will gain additional R value, but the extra two inches will not perform any better than the 3.5 inches. Once you have created an air, vapour and thermal barrier, you have overcome the main object of defeating air leakage. Spray the foam directly to the underside of the roof without an air space.

The foam will stop the warm moist air from inside the house reaching the cold surface of the roof. If the warm air cannot meet the cold substrate you will not get condensation so there is nothing to vent.

I typically spray the underside of the roof deck from the eaves to the attic floor, across the attic floor and then down the other side of the roof. Don't forget to spray the gables inside the crawl space area. You will obviously have to remove all the old insulation first.

This method allows the crawl space areas to become conditioned. You could add additional storage, closets or recessed drawers into the crawl space.

Check local codes for the requirements of a thermal barrier.

I am in Ontario Canada, I assume a similair climate.

You need to login to reply to this topic. Please click here to login.