How Many Posts To Support A Roof

Patio roof posts columns.

How many posts to support a roof.

According to the old af pa table a 4 foot douglas fir 4x4 post can support 256 square feet of deck. The second factor will be the depth these posts are planted in the ground. The international residential code requires railings on any deck that is more than 30 inches off the ground. The length of your posts will help determine the height of your carport roof.

It was 16 wide x 40 long. In all probability for this size deck you need to be talking 3 rows of support beams with 3 4 posts each one beam near house one near outside edge one down the middle to be able to get to economical and realistic joist spacing 16 or 24 and realistic post size 4x4 or 6x6 and beams 4x12 or smaller. Sometimes they e built up from more than one size of lumber. Here we look at the most common.

How many deck posts should a 8 x12 deck have. For post material choose one such as pressure treated pine that will resist rotting and insect damage when it is planted in the ground. In other words the maximum distance it can cover without support from posts. Most builders use 4 by 4 inch lumber.

Large 8 x 8 posts are necessary for the use of supporting a porch roof. We just completed a beer garden addition with a single sloped roof. Porch decks also require larger footings than deck footings. Any post that will touch the ground should be pressure treated for decay resistance.

Solid lumber such as 4 by 4s 6 by 6s and 8 by 8s. For deck roof posts dig holes for the roof posts and pour cement to keep them secure. The span on your porch posts is determined by the weight load of the roof. The determining factor of post spacing is the allowable span of your beams.

Posts and footings support the weight of your house so you have to size them right. Consult with a structural engineer local building officials and contractors who specialize in this work. Load bearing posts must have a solid footing on undisturbed soil and all parts of the post must be fastened together. Step 2 post height.

If the deck doubles as a porch it needs to be able to support no more than 80 psf. Posts and columns may be made from several types of materials. Measure the distance between the bottom of the porch roof and the top of the ledger beams of the porch. However if the spacing is too wide the patio cover s beams will bow under the weight of the joists and roof covering materials.

Using the 2005 nds i calculated that the same post can support 231 square feet so it would seem there s no problem using 4x4s to support say an average sized intermediate stair landing.