Building a deck over a flat roof is very similar to building a deck over a concrete patio.
How to build a rooftop deck on a sloped roof.
Photo by dave holbrook.
Since most roof decks are floating structures that sit on top of flat roofs it s crucial to weatherproof the roof below the deck to prevent water from seeping into the home.
In this article builder emanuel silva shares his method for building such a deck which begins with a leak proof low slope roof of epdm rubber.
First you must make sure the roof is strong enough to support 55 lbs per square foot.
If the span under your deck is 12 ft for example the purlin at the outer end of the deck should be 3.
One of the challenges in building a deck on a roof like this that s unlevel is the deck needs to be level.
Much of the work that s being done here is identical to what you would see on any deck built in a suburban backyard.
A deck on a sloped roof requires a different approach to the framing underneath the joists.
Careful detailing of membrane roofs at corners doorways and penetrations is critical for long term performance.
But the rooftop location does offer some unique challenges particularly in regard to the deck s foundation.
The roof deck surface should sloped away from the house a minimum 1 8 inch per foot so the water will.
This is usually because low quality leak prone decking materials such as epdm rubber are used often in an effort to save money.
How do i flash between post and roof.
They are merely placed on top of another structure.
Hardwood decking is then fastened to tapered pressure treated sleepers that rest on additional strips.
Building a deck above a porch roof allows for sheltered space below and views from above.
Make the front of the roof the height of the house roof you are presumably tying into with the rear sloping at a rate of six inches over two feet.
Before installing a roof deck you must be certain the roof is stable and weatherproofed.
My plan is to open up the roof and sit a couple of 4x4 posts on top of the outside wall.
Of roof decking costs 800 2 800 to install depending on the material you choose.
Roof deck framing unlike for decks at ground level doesn t entail a ledger attached to the rim joist of a house.
How to build a deck roof.
These decks are often referred to as floating as they are not secured in place as a stand alone structure.
Some key details for a leakproof rooftop deck are.
Plan to space the 2x4 purlins parallel to the house and 3 ft.
Tie your existing deck posts into the roof by extending your corner posts with the 4 by 4 lumber.
Instead a pair of beams rest on supports called sill plates to create a frame for the deck.
Epdm is the best choice for most rooftop decks.
By john fenton n b canada i want to build a deck on a sloped roof.
Unfortunately many homeowners who have a flat deck roof have to deal with frequent leaks.
On average 300 sq ft.
