Is My Attic 2x4s Or 2x6s

My calculations tell me assuming 2 southern yellow pine joists which are common in my area that 2x6s 16 inches on center will span 9 feet 9 inches with allowable deflection being the governing factor.

Is my attic 2x4s or 2x6s.

Steve demoor of wildlife solutions takes you through a first hand encounter with extensive attic damage due to squirrel problems in a home. The attic joists are only 2x4s and are 27 inch on center i double checked. Jumping up and down may reveal little or no bounce in attic floor but it s not the same as when furniture and books are added. If you do this you can plan what size 2x4s you want to purchase then see if there s a good combination so you are left with the least amount of scrap.

To the ridge simple sistering with 2x6 s should be strong enough for the amount of weight you d ever be likely to put up there. But if you only have 3 4 ft. Many older homes have actual 2x4s not the 1 1 2 x 3 1 2 that we call 2x4s today. That means that for a 2 400 square foot house the interior of a 2x6 built house will be about 33 5 square feet smaller overall than that of a 2x4 built house.

If you have room to stand up then the strongbacks look like a good idea. Because 2x6s are 2 inches deeper than 2x4s a house built with 2x4 vs 2x6 walls will be a total of 4 inches wider and deeper inside than the same house built with 2x6s. If joists are only 2x6 they may need reinforcement. But you can still double the capacity of the existing 2x6s in the attic floor so first let s make sure that s enough for your situation.

My ultimate plan is to sister the joists to make a sturdier attic ceiling blow in insulation on the roof and put plywood across the joists for a storage platform for my boxes christmas decorations etc. But i want to do it right and if 2x6 would be way better i ll do them. When you start a 2 4 project you can figure out all of your measurements in advance. I talked to a structural engineer and he advised to sister the existing 2 4 joists.

For example if you need 4 5 cuts of 2 4 you want to buy 2 10 2x4s instead of 4 8 2x4s. A lot depends on how much height you have available in this attic. If the answer is to get a structural engineer then that s out of their budget so we ll just probably be forced to put in the 2x6s though i bet the 2x4s or sistered 2x4s would actually be enough for such a low attic space. The building inspector should be able to check things outs.

Only reason for not choosing something bigger than 2x4 would be that they will be significantly cheaper if i can get away with them.