Bay Window Roof Framing

First the instructions to find the ridge length is wrong.

Bay window roof framing.

Unlike a traditional hip roof the roof over a bay window with 45 degree sides is based on an octagonal roof but most people don t know how to frame an octagonal roof. It looks like diy built the bay window roof. This bay window rafter script will print out a chart of all rafter lengths and angles for the baywindow. Drawing bay roofs out full scale is key to fast and accurate framing.

A projection with four or more angled faces is a bow and cannot be calculated with easy rafters. By scott mcbride issue 129. Bay roof a bay roof is a three sided roof framed against a vertical wall of a building usually covering a projection from the building such as a bay window or breakfast nook. This article explains how to lay out framing members with the help.

But once the window its frame and its cap are in place you can get started framing the roof. Most of the time a bay window will have a hip roof that s constructed using 45 degree angles. We asked one of our veteran builders to show us how it s done. Do not use this method to framing bay window roofs.

The starting pitch is 3 12 and the ending pitch is 16 12. It s wrong and just plain ugly. Step 1 plan and install the bay window. It s time to finish planning the roof frame.

Then miter 4 joists at a 45 degree angle on both sides and install them around the exterior opening of the frame to reinforce it. Plan carefully consulting with the architectural plans before commencing work. Once the window the window frame and the window cap are all in place and have been secured and insulated you can get started on framing. Roof framer s bible framing a bay window roof page 206 does not follow the holly grail of roof framing trigonometry and geometry.

The secret to a good looking roof is having the right proportions. To build a roof cab construct a wood frame out of 2 by 4 ft 0 61 by 1 22 m boards that matches the base of your bay window s roof and mirrors the shape at a 90 degree angle on your wall. Before you get started with the roof the bay window itself needs to be in place. Framing a bay window roof it s only a small hip roof but its 45 degree corners befuddle many carpenters.

You ll also have to plan for the bay window roof.