Monday 16 March 2015

How to build a Pergola – Step Eight

Step Eight- Installing the Rafters and Ridge

Once the frame and the posts are installed, your pergola will look like it is beginning to come together. It’s now time to receive the payoff from your earlier work assembling gable frames. Erecting the gable frames is a quick and simple step and will leave you with what looks like an almost finished gable pergola. Putting the frames up is probably the easiest and the most fun part of your project.



The frames are installed with a minimum of two people per frame(Illustrations here only have one person, but we recommend two) To put them in place, stand a ladder at each beam below the corresponding joist hangers which you have already installed. Lift one end of the gable frame into one of the joist hangers so it is pushed in as far as possible.


With one person holding the end that’s in the joist hanger in place, lift the other end up to the opposite joist hanger and slip it into place also. Ensure you keep the first end of the gable frame securely positioned in the joist hanger while you do this as you could either break your gable frame or injure yourself if the frame falls. Once both rafters are in place push both down firmly to ensure they are positioned completely in the joist hangers and against the beams.



Once the gable frame is up and firmly in place, secure each side by driving a flat connector head nail into each hole of the joist hanger.



Repeat this process for all of the gable frames in your structure. Be careful to make sure that you position all of your frames with the collar ties on the same side.
Installing the ridge


Now that all of the gable frames are up and securely fastened you can move on to installing the ridge. The first step in installing your ridge is to gently slide it into the gap above your collar ties and below your rafters. The ridge should sit on top of the collar ties and run the length of your pergola.



With a ladder at each end alongside the bottom chords, 2 people should be able to lift and push the ridge beam into position in the gap at the top of both sets of rafters. Make sure that when you do this the notch in the ridge is on the under side.



Once in position, the top of the ridge beam should line up with the top of both sets of rafters. The rafters will support the ridge but you should be careful not to push it too far up as it can be quite difficult to pull down. Once the ridge is in place you can use your spirit level to make sure the end of the ridge is lined up with the outside face of the bottom chord.

If the centre of the rafters do not line up with the marks on top of the ridge you will need to tap them into place. Do this using a block to protect the timber of the rafters from damage by the hammer.



Once the rafters are in place fix them to the ridge with 3x75mm nails, 1 in from the top of the rafter and 1 skew nailed in either side. As you fix each gable frame to the ridge you can also fix the 600mm rafter strap over the top of the rafters and ridge. To do this, use 5 connector nails in the holes on the strap on each side of the ridge.



Now that you have completed and fastened your gable frames and your ridge, you can move onto the next step, which is the installing gable ends and purlins.


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