How much weight can this flat roof hold?
Question:I want to build a patio on top of a flat roof, which is the roof over my breakfast room. The studs on the roof are 2x6s, 24" apart on center. The roof is about 12'x13'.
Now, I need to build a floor for this patio. I thought of placing the 2'x2' concrete pavers on there, but I don't know if it would hold it. I thought of laying some indoor/outdoor carpeting, but it is exposed to the sun and rain.
1) How much weight can this roof hold?
2) What do you think would be the best floor for this roof and why?
Answers:
Don is incorrect about a couple things. When a roof is flat, the roof "rafters are called roof joists unlike ceiling joists. The roof is under framed but i wouldn't be all too worried about that as it shouldn't cave in unless you had unusually heavy snow loads. If you want to put a deck out there, don't rest any load on the existing roof. If you put the deck supports over the exterior or load bearing walls so that the load directly transfers to the foundation, then you won't have any issues. Deck joists definitely should be 2X10 on 16" centers though. As one of the answers suggested, you may want to replace the roofing before doing the deck work because once the deck is there, how do you gain access to the roof? EPDM rubber is a great product for the size of roof you are dealing with. It isn't much of a DIY job but good luck.
Your roof is too light by half to hold the weight.
DON'T DO IT! your roof is not adequate! for a 12' span, your joist should be 2 x 10 minimum at 16" on center.
When you re-build your breakfast room roof, there are membranes that are set up for this type of application. Google rooftop patio systems.
Your roof now won't hold the additional dead and live load weight. The new roof deck finish needs to be decided first, so you know how much more weight you are adding. The heavier the material, the more you will need to modify your structure. As a new walking surface, you will also be adding a 'people' load.
You can then hire an architect or structural engineer to check your foundation and size your joists, and give you the re-assurance it won't collapse.
I agree with everyone. I am actually surprised that it held the weight of the roofers. Those are "rafters", not studs. Studs run vertically in a wall. Joists run horizontally in the floors, and ceilings. Rafters, and ridge boards form the roof.
I suggest that you exercise caution when walking on this roof. One rotted spot could cause a nasty fall. I also wonder about overhanging trees. If a branch fell on that, it would do serious damage. Find a different room during a storm.
If your span is 12'x13 and the joist which I think is what you are referring to as studs are 2' apart I wouldn't plan on doing much out there. The 2 foot centers and only 2x6's and concrete pavers? Bad, bad idea?
I would say if you absolutely have to have it and your mind is made up the only way that you will have half a chance is find the middle and put a beam to help hold the weight. But still I don't like the 12 feet x 13feet with 2x6 joist on 24" centers.
If they were 2x12's maybe 10's on 16" centers you might be able to get away putting concrete pavers on it. I wouldn't but you probably can. With 10's you will get a bounce. I would say DON"T DO IT.
More Related Questions & Answers...