What to Consider When Adding a Roof to a Deck or Patio

The best way to cover a deck or patio is by building a permanent roof over it that’s attached to your home. While it may be more expensive than a temporary cover or awning, a roof will last longer and add value to your home.

Before attempting to construct a roof over your deck or patio, consult a professional builder to make sure the design will meet local building codes and is strong enough to stand up to high winds.

Watch this video to find out more.


  1. Felt roofs (AKA: Built-up roof) are made from ashlapt and ashlapt-saturated felt roofing material typically designated by weight per 100 square feet. So, 15-pound felt is 15 pounds per 100 square foot. Such roofs are laid up in multiple plies sometimes with a heavier top ply, which sometimes comes with a mineral surface (similar to shingles). These roofs are mopped down in hot ashlapt. There are coatings that may also be applied over the roof to extend life and increase its insulating value and so forth. Rubber roofs (AKA: EPDM) are single-ply roofs made with a thin rubber membrane laid over either a smooth insulation or recovery board’. The material is either glued down or mechanically fastened. Their insulation value is only in the substrate, not the material itself. And, although there are coatings that are compatible with EPDM roofs for reflectivity and life-extension, they are only moderately effective. Both of them can come with very long warranties, with industry-standard varying between 10 and 20 years, and limitations from visible leaks only’ to NDL (no dollar limit) warranties. EPDM roofs are cheap, go down fast, and work quite well if done properly with all the correct details. HOWEVER!! They are prone to mechanical damage (step on a nail while walking across an EPDM roof, all of a sudden there is a hole in it). They also come in various grades from 0.045 un-reinforced to 0.060 reinforced fleece-back. The former is c**p, the latter relatively expensive but very resilient and stable. Bottom line: If this roof has a lot of traffic on it, or is subject to mechanical damage, an EPDM roof will be a nightmare. But if you have a normal roof and can control traffic on it, EPDM is very cost-effective.There is another material (TPO) that is an ethylene propylene rubber membrane similar in application to EPDM, but white in color. It is fractionally more expensive than EPDM, but is heat-reflective. There is also a system (trade-mark DURO-Last being one brand) of reinforced PVC roofing that is engineered in a factory and delivered in only a few pieces even for very large roofs. This would be the ideal single-ply roofing system if funds allow. The compromise between built-up and single-ply roofing systems is something called a modified bitumen system. It is much higher in cost than single-ply (but less than a properly installed built-up roof, barely), but is tough as nails and can be warranted for as long as 30 years. Where money is no object, this is the ideal flat-roof system for moderate and high-traffic roofs. Then there is ballasting an entirely different discussion.

  2. porch roof—about 20′ x 18′–HAS WORD/PARTICLE BOARD—leaks and is water soaked—needs replaced. CAN IT BE COVERED OVER INSTEAD OF RIP OFF—USE METAL OR VYNILE FIBERGLASS—NO ashfalt/ clay—-cheap but good! Need discount if possible what would work for old 76 year old.TIRED OF BEING RIP OFF BY >HOME ADVISIOR people

  3. Hello,
    This was very helpful!
    We just started building our roof for a 16×24 foot deck. We used 4×6″ posted and used tapcons to attach to the brick house with 4×4″ headers. We ended with 12″ of drop from the back header to the front header. Question is that enough? There is 3/4 of an acre between the house the tree line and we get 12-14″ on average of annual snow fall.


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