Framing A Pitched Roof Over A Flat Roof

If excessive damage is present you might not be able to do this at all.

Framing a pitched roof over a flat roof.

A common house roof pitch is 5 by 12 which means it slopes up from the wall at 5 inches per foot. The hip pitch in relation to the secondary roof measures out at 9 5 8 18 13 16. Flat roofs aren t architecturally logical as rain and snow will shed much more quickly off a sloped roof. Building a pitched roof over an existing flat roof it depends on a lot of variables like the condition of the existing flat roof including the state of the joints and the material its made of.

Yet for historic modern style buildings like this old house s cambridge tv project flat roofs are at the core of the architecture meant to reflect the broad horizontal lines of the natural landscape. These requirements cover the design and construction of roof ceiling systems including roof framing roof drainage roof sheathing ceiling finishes roof ventilation and attic access. Make sure the pitch of the trusses is the pitch that you want for your new roof. Of course you don t need to live in a modern house to deal with a flat roof.

If you re adding to the gable end of the house the side wall that goes up to the roof s peak it s fairly easy to extend the existing roofline over the new space says curt schultz a realtor architect builder in pasadena calif. Installing a new roof over an existing one also called a layover or nailover is often possible although not always the best option. You ll have to find the secondary roof hip pitch the same way you found the main roof hip pitch as in figure 3b. If the structure contains windows then you ll need a low pitch for example.

Premade trusses will form the skeleton of your new roof above your old roof. This is a completion video of a flat roof framing. How to install a roof over an existing roof. Chapter 8 includes specifics for such things as allowable lumber to use the moisture content of fire retardant treated wood allowable rafter spans and use of.