I want a lot of shade under my Pergola. Can the spacing of the roof rafters be set at 2 or 3 inches on center and what would be the additional cost?
The roofs slats can be set closer together at whatever spacing you like. However, going to just 3 inches on center will create much more shade than you are imagining—it will create almost a closed roof. The slats are 1.75″ wide each. At 3 inches on center, you only have 5/8″ of an inch of open space between the each slat. You’ll block the view of the sky completely and have over 80% solid wood on the top layer of the roof. If you then figure the 5.75″ tall rafters below are set at 18 inches on center and also block a lot of sunlight (since the sun is at an angle most of the time), you will have nearly 100% shade under the pergola at most hours of the day except when the sun is directly overhead. The extra roof slats will add 11% to the original cost estimate. If you still would like to proceed, consider a maximum of 6 inches on center when doing the assembly (don’t screw them in—just place them at 6 inches on center) and see how it looks and how much shade it provides. Then, after a da
