I’m drawing up plans for my house i’m building. My question is what size sills should I use.
There will be concrete filled blocks on 18″x18″ concrete runners. These will be on 12′ centers throughout.
I was thinking of using 6″x6″x 12′ treated timbers, or should I go with 8″x8″x12′ sills?
My floor joists will be 2″x10″ untreated pine.
I would appreciate any help on this matter.
Replies
HI there,
I am not sure I understand what you are planning for the foundation. Can you explain your idea a little bit more? Not sure what you mean by concrete "runners". I wonder if you mean footings? If your plan is to frame a floor on concrete piers, then what you are asking about is really beams, not sills. Sills for houses built on foundation walls or slabs are generally treated 2"x6", but they don't have to span as they are fully supported by the concrete below. Wood members spanning pier to pier would be beams. There are span tables available that show what size, material, and spacing is required for the beam also taking into account what type of load will be placed on it. If you can explain a little further, I think people here on the forum can probably get you started in the right direction.
question about beams
Thanks for the replies.
My footings will be 18"x18" with rebar cages 12"x12". On top of the footings I will have concrete blocks, concrete filled with rebar tying it into the footings.Connected to the blocks will be 1/2"x16" anchor bolts for the beams.
These footings will run the perimeter of the house, also 3 running from front to back tying into the perimeter footings.
The blocks will be on 12' centers. The blocks will be 3 blocks high. Approx 24" high above the footings.
The house will be a 1625 sq. foot house. one story, all wood with hardie plank siding.
The soil is approx 2000 psi
Most of the beam span tables I have found consists of 3 plys of 2"x10" etc. I have not been able to find one using solid wood beams.
I hope i haven't missed any information. If so please remind me.
Thanks for the help.
what the heck is a 18 by 18 cage?
cages?
floor beams
This will be 36' long. 12"x12" high, made of 4 pieces of rebar with a bent square for stability every 2'.
most footings ...
most footings run full length and are 8 to 12 inches thick and 16 to 24 inches wide.
footings
This will be 18"x18"x36' footing.
18 inches deep is way way way over kill
overkill on thickness.
If you want or think you need stablity, make teh footing wider. Go for 10 or 12 iniches thick (12 is still over kill) and 24 inches wide.
Remember you are looking for bearing. If you have 2000 pound per square foot soil, your 18 inche footing is good for 3000 pounds per linear foot. 24 inch wide is good for 400 pounds. Your 18 inch thickness buys you nothing, unless you are afraid a 12 inch thick footing is going to break clean through and then move. (NOT GOING TO HAPPEN)
Go for 10 inches thick , 24 inches wide. Much better than an 18 x 18.
footing
Thanks for the info. Like I said, i'm still in the planning stage. Easier and cheaper to fix on paper.
I would still like to find a beam span chart using solid wood beams instead of plys of 2"x10"s.
sorry
24 is good for 4000 pounds not 400
It would help folks here understand your needs if you told us a bit more:
Where (what city, what climate) is this house located?
Is this intended to be a year-round residence or only a summer home/weekend cabin?
How will the house be finished, inside and out? (Not the tiny details, but type of siding, type of flooring, etc.)
question about floor beams
This will be a full time residence built in southern Texas., not near the gulf.
Hopefully all wood interior with hardi plank exterior.
Sounds complicated to me. Why not CMU knee walls around the perimeter, piers in the middle with tripled 2" X 12" girders and LVL or floor trusses spanning the whole thing. Actually the floor trusses would probably span the whole thing without the central girders. What's the standard for your area?