Flat Roof

[Al]

Ok... Well, I am currently buildig a small addition to my sons fort (treehoude on wooden 4*4's. I am going to do many creative things, like having an outdoor brick fireplace. Anyway. I have my mind set on a FLAT roof, with a drain. I want the addition to look similar to my 1950s home. My questions are: The roof will be small, sort of an expirament. The whole thing is only going to be 8ft*6tf. I am going to put tar paper, then roofing tar. There will be 2*4s on the surface, at the edges, covered in tar, so that no water will go over the edges of the roof. I want to put in a drain in the middle. I was thinking 1.5 inch PVC ??? any suggestions would be appriciated.

[I-zheet M'drurz]

Uhhh, yeah! Why ask for leaks? Solid roof, sloped about 1' over the 8' run. Gutter. Downspout. Hell, 60's homes had gutters and downspouts, didn't they? lol

Seriously, making it totally flat would be inviting pooling and leaks, poking a hole in the middle of it would just about guarantee it eventually.

[Phisherman]

Unless you are in a desert, the roof won't last very long. A slight pitch with a small gutter on the edge is a better plan.

[Al]

Yea.. I was thinking of a very slight slope towards the center. This is how they do it on industrial buildings, which rarely have roof leake (Mind you... All the plans were drafted by my 14 year old son) :)

[Terry]

Similar to a tree house? Built small shed 6 by 8 feet approx. Mainly out of wood/plywood on hand. Kept it low with a basically flat roof so it wouldn't project above a fence and be inconspicuous. Roof is flat and 'looks' level. But is actually slightly sloped the full depth (3.75 inches) of one two by four in one direction and by 1.5 inches in the other, so that water and melting snow drain off towards one corner. That corner was chosen as most suitable for drainage and is away from the shed door and the one window which are both in the middle of two of the walls. Roofed with two rows of new heavy 36 inch (approx.) wide felt and one row of 18 inch (approx.) wide felt with big overlaps; used galv. roof nails but not the ones with the big rustable tin washers and some black roof adhesive. Despite our winds the roof nails seem to do OK on this 3-4 year old shed and another pointy roofed one, which is about 20-25 years old. Six inch roof overhangs keep drips away from outside walls. No gutters. Hate gutters; they are an invitation to rot in the soffits and or damage from ice, snow build up and ladders! Also gutters can get full of leaves which can then rot and smell! Shed has withstood several winters including a heavy accumulation of snow which I feared might have cracked the two by four roof rafters; but didn't! No tar. No leaks or problems. Good luck.