How to Build a Gable Roof?

Hi there,

In my past 7 years of construction career, what I have seen is that, one of the most common roof styles is the gable because of its appealing symmetrical shape, effectiveness at draining water, and potential for attic space. If you’re wondering how to build a gable roof, let me tell you that all you need is some basic carpentry equipment and know-how to build a gabled roof, but you can build a roof for any straightforward structure as long as you take accurate measurements and cuts. I will share a step-wise process of how to build a gable roof without ceiling.

How to build a gable roof overhang?

1. Wall plates and Joists:

   The joists should be cut or fixed so they are level with one another and level with the back border of the wall panels. The wall plates should be spaced at whatever intervals you might need for your gable roof.

2. Ridge:

   Determine the width of the barge soffit planks. Add the gable roof size twice, once per gable end, to the building's total length. With an equal protrusion at either end, cut a vertical piece of crest content to this length and install it on the wall plates.

3. Common rafters:

   Gable roofs only make use of regular rafters. Compute the rafter lengths with the overhang included using the measured span. Before cutting the rest, cut a pair to make sure they fit. To utilise the staircase trusses (barges) on the outside, four additional rafters should be cut to length without the birds-mouth this time.

4. Get the rafters up:

   Two pairs should be nailed to the wall plates. Keep the tops loose so they can rest against one another for support. The rafters should pinch the ridge board as you push it up between them, holding it in place.

5. Ladder trusses:

   The last rafters just need to be nailed to the wall, following which noggins can be cut and fixed at 400 centres. To create a ladder truss, flip it over, place the rafter without the need for a birdsmouth against this back to back, and move the noggin locations onto it.

6. Fill up the gable end:

   First, support the ridge by placing a vertical piece of wood straight up. To support the noggins that make up the ladder truss, place two plates laterally from the wall to the one that was just installed under the ridge. At 400 centres, fill up the remaining space to close the gaps.

7. Collar ties:

   To receive the benefit, collar ties must have seats cut into either end and be fastened level. Maintain a seat cut that is about 10mm backwards from the rafter's outside edge.

8. Purlins and struts:

   For the gable roof to hold the load of the roof covering, struts and supports are required.

These are the steps I follow for how to build a gable roof. I hope they help you too.