proprojects

How crazy would it be to turn this 100% unused attic area into a rec/living room, bathroom, and bedroom and what headaches am i going to run into? I am a "handy" individual but I am no contractor.

http://i17.photobucket.com/albums/b56/PROPROJECTS/HOME/IMG_3828.jpg

nealtw

After you have the roof off is not a good time to be looking at this.
As you have rafter and not trusses you have a better chance than most. Your first trip is to the city. They will tell you if it is allowed and how detailed a plan you need and if you need an engineer to be involved.
Besides changing the roof lines you are adding floor joists and bearing points all the way to the foundation and maybe underpinning there. You will also be looking at stairs wiring and plumbing.

proprojects

What are the chances that the current ceiling joist hidden by the insulation could also support the floor? Do they need to at least be a 2x6, 2x8 or 2x10 to support a flooring substrate? The house has a new roof on it now, I was looking to open up the gables on the ends and adding in bay type windows.

BridgeMan

From what little I can see from the picture, I think the attic would be a good candidate for making into additional living space. It appears the roof rafters are 2 x 6s, on 24-inch centers, and are being given additional support by the diagonal kickers. The kickers would of course have to go, but the pony walls you build on each side will easily replace them (if properly constructed). The 2 triangular spaces behind the pony walls would make good locations for running your new wiring and possibly plumbing, and if you run the new floor sheathing all the way out to the rafter bottoms, the spaces could make good storage locations as well. To properly insulate the attic area, you'd probably need to increase the rafters' depth to allow space for some R31 batts before sheetrocking.

Regarding the floor joists--the type of wood, grade, joist spacing, joist depth and wall configuration in the living level under the attic all need to be evaluated by someone qualified to do so (licensed engineer in your state) to determine if the existing members are adequate or if and how they can be strengthened to support the new living space loads. The bottoms of the kickers in the picture are probably located at interior walls, which would increase the likelihood of the floor joists being workable because of shorter effective span lengths.

nealtw

The cross bracing that ties from the center of rafters back to the center of the house would have to be replaced with the pony walls and have to land on something that can support the weight, so you would need at least 2x10, 16" on center from a center wall to the outside wall and you probably do not have room on the outside between the wall and the roof sheeting for a full 2x10. You would be adding 100 pounds per sq. foot before furniture. Would your stairs run in the same direction as the rafters or not?
It's great to look at all this stuff but the foundation and footings are the real question.

BridgeMan

nealtw, it sounds like Canada has more conservative design load codes than here in the U.S. (heavier people up there, eh?). Although I am not a design engineer, I think the 100 psf design load you're suggesting is a bit too high. My copy of the IRC, Section R301, calls for bedroom floors to meet 30 psf live load. Adding another 10 psf for dead load, and even throwing in a roof snow load factor distributed through the pony walls would probably add only another 20 psf or so, for a total of 60 psf.

Another thought--if the existing floor joists are only 2 x 8, the floor could be made workable by either sistering in (doubling up) additional 2 x 8s, glued and screwed, or even splitting the existing joist spacing in half by inserting new 2 x 8s between them.

nealtw

Bridgeman: Like I said , we need an engineer here. When removing cross bracing adding load bearing pony walls near the center of the floor joists. I will over estimate the weight every time, and let the onsite engineer correct me.

oldognewtrick

And we have a winner! I remember a house not to far from me that was a ranch style house. The homeowner thought that it would be a good idea to add a second story and double the living space. Permits?? Nope, didn't need them. Engineer??? nope didn't need to spend the extra $$$ for a engineer. Consult or hire a contractor??? nope, all they do is take/cost the money. Well guess what...yep dropped the hole structure inside itself, luckily no one was killed. Bulldozer, clean earth, new building...

If you're planning on changing load points, cutting bracing/changing rafters get some advise from someone who understands building dynamics.

BridgeMan

All right, I confess. I'm a semi-retired civil engineer, first licensed in 1971, at one time licensed to practice in 7 states (but currently only licensed in 3, as it's too darn expensive renewing them when I'm not bringing in the coin). To date, I've performed more than 3550 structural inspections of residential and public infrastructure facilities in 12 states. But contrary to the majority of engineers I know or have worked with, I still practice the more conservative working stress design method when asked to crunch numbers, and I'm not afraid to look at the practical side of things, nor do I hesitate to use logical common sense when addressing challenges and problems. Oh, and did I mention that I love getting my hands dirty, working with steel, concrete and timber construction?

inspectorD

Looks like a job for an engineer ....actually on the job, from my couch anyway.

Looking at the skip sheathing for the wood shake roof that used to be there, and the non- dimentional wood from a factory setting, I'm wonderin what the foundation is for the house of that age....and if there are any bug infestations from the non kiln dried lumber common to the older homes.

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