Roof Window Between Rafters

Widths tend to be based on the standard spacing of timber roof rafters.

Roof window between rafters.

The standard for roof windows is 900x600mm and these are installed between rafters at 600mm centres. If you have an easy roof to vent and decide to go that route you could use mineral wool insulation between the rafters and beneath the vent channels. Velux roof windows for example are available in sizes from 470 x 980mm to 1340 x 1600mm and 940 x 550mm to 780 x 1800mm angus says. Choosing windows narrow enough to fit between roof rafters or trusses is a good idea that will keep your costs manageable.

Roof construction and timbers framing a roof window if your roof window fits between existing rafters or truss work it can be just a simple job of fitting the window to the existing woodwork or adding some timber framework to take plasterboard at a later stage. In heavy duty construction a ridge beam might be used instead. The rafters are 4inch by 2inch on approximately 400 mm centres and extend around 7ft from purlin to ridge apologies for mixed units. If you choose or need to go with an unvented roof you would need either exterior insulation or a flash coat of closed cell spray foam first then you could round out the insulation package with mineral wool.

Where the conservation rooflight is required to sit flush to the roofline within narrow roof build ups below 98mm from the top of the structural rafter to the outer face of the roof tile we recommend a between the rafter installation. The ridge board must be the same width as the rafter boards. Installation on rafters is recommended especially when we replace old windows in already existing roofs with new ones or when we install big windows. Standard diameters for tubular skylights are 10 inches 14 inches and 21 inches sizes that allow the skylights to easily fit between roof rafters or trusses.

So you can get small ones or wide ones or long ones but you can t get long and wide ones. We install windows on rafters when the window width matches the spacing between rafters it ensures stability of the construction and the durability of the connection. Installing and flashing the window itself will cost 200 to 300 for homes with asphalt shingles and 20 to 30 percent more for metal or tile roofing. The windows are placed on the same level in the slope with just over 800mm of roof surface between them.

Rafter boards are fastened to the ridge board at the peak and the top plate where they join the wall. They can also be provided in much larger sizes for example glazing vision pitchglaze windows can measure up to 3000x1000mm.