Learn All About How to Build A Pitched Roof Extension DIY

Pitched roofs are the type of roofs that have slopes instead of flat surfaces like flat roofs. The slope can go on both sides, but sometimes, roofs only have a slope on one side. Sometimes instead of a whole roof, only kitchen extensions have a pitched roof. It all depends upon homeowners and how they want it to be. These roofs work best for areas with higher rain or snow rates in seasons.

a cottage house with piched roof extension and a big garden.

Do you want to build a pitched roof for your house too? Then this article has some workable steps which will make you a pro at this! So let’s give roofs of our houses a little pitch with these specifications.

How to Build a Pitched Roof Extension

There is no doubt that building a pitched roof is more of an engineering task. But if you have all the materials and proper guidelines with planning permission, then you can customise your roof all by yourself. 

This article contains a proper guide path to make an inclined roof for your home. Let’s go through this workable process step by step.

Things You’ll Need

  • Calculator
  • Pencil
  • Paper
  • Measuring tape
  • Plywood
  • Underlay
  • Timber battens
  • Roof covering
  • Roofing nails
  • Truss material
  • Levelling scale (or a laser level)

DIY Steps

1. Preparing a location

The first step in the process will be preparing a location for the roof. The location will be above your building works, but the issue can be any structural interruption. The structural interruptions will include electric wires, branches or built structures.

a close up of a man measuring the roof beams distance

Manage to clear the location so that you can continue with the flat roof loft conversion process without any hindrance. Ensure that you have the planning permission from the required building regulations authorities before changing your flat roof.

2. Calculate and decide the pitch of a roof

First of all, you will have to decide how much pitch you require. Depending upon that pitch, you will make a ratio. If you want low pitch, then the ratio will be 4:12. Similarly, if you want a higher pitch, then the ratio will be 6:12. That means that if the roof is vast by 12 cm horizontally, the roof will rise by 6 cm vertically.

3. Calculate the material required

After knowing the extent of the slope, you will be able to calculate the area of your roof. The material and its cost are standard in every area, which can be calculated if you know the roof area. So once you know about the roof area, you can easily calculate the roof material required and its cost. 

4. Planning a design

Do not start without preparing the design for your pitched roof. You will have to decide the pitch, and according to that pitch, you will plan at what angles your roof will be inclined, and the frame will be fixed. Also, making a plan concerning width and length will assist in making the exact layout of the roof.

5. Levelling the roof

After planning a design, you will start working on implementing the plan. The first step in this regard will be levelling the existing surface of the roof. After making sure that the surface is levelled with the help of levelling scale, move on to the next step.

6. Raise support for the roof 

The next step is raising the support framework of the roof. First of all, place the supports at the roof corners. Then, distribute the rest of the supports between the corners, ensuring the distance between these braces is equal.

7. Install the braces

You will need a support system to sustain the rest of the roof braces. Temporary braces can help you in this regard the best. You can simply remove the braces. To install braces on single-storey extensions, use nails to fix a board of relative size from the centre to the back vertically.  Place the braces of the same height at the sides of that central brace. Install the braces on the front side in the same way, which will act as front and back wall support. 

8. Fixing the braces

Now you will be required to fix the brace to complete the frame of your roof. It should have a length slightly longer than the existing braces to be fixed on a central brace. Now after completing the braces of one side, try fixing them on the other side. 

9. Make the central support

To support the pitch of your roof, you will need to make arrangements. You can use a timber truss as support, but for that purpose, the length of the timber should be compatible with the size of the roof of the building. Fix the joist along with the braces for central support.

10. Add roof joist

The next step is attaching the roof joists with horizontal braces of the building.  These roof braces will be placed at equal distances at regular intervals to give the inclined shape to the frame. Once this is complete, you will see that your roof frame has adopted the shape of the roof.

11. Install permanent bracing 

After the braces are installed in the frame, it’s time to go for permanent braces of the frame.

12. Add sheathing to the frame

As your frame is complete, now you will install sheets of plywood. You can always choose sheets of your choice but make sure that these sheets sustain the structure of your roof. Use nails and a hammer to fix these sheets.

a man wearing a protective uniform installs wooden plank to build a piched roof extension

Keep on fixing the sheet until you are sure that it will not come off. You can also go for thermal insulation if the weather of the area is cold. Your nails should be 10 cm inwards from the edges. 

Make progress with your sheets in rows because it is difficult to cover the whole roof at once. You can also leave one row and install glass if you want to make the inner area store. It will provide natural light in store. 

13. Fix drip edge

After sheathing, you will need to fix the drip edge. This will be fixed along the edges of the roof. Though the water will slide automatically due to the roof, it still requires structural adjustment to address the issue.

14. Add the underlay

The underlay is necessary for waterproofing your roof from any unpleasant weather conditions. It will make water slide in the drip edges of the roof, and from there, water will be forwarded to the ground. You can direct the water flow in a direction that can be used to water your plants in your living space.

You can also use guttering to dispose of water. Install the first piece of underlay and follow up this for successive pieces with equal intervals. Furthermore, fascia and soffit boards might be necessary to cover any cables or wires.

15. Add the material of the roof

Different types of tiles or plates can be used to add the roofing material. Depending on your preference, you can use roof tiles, shingles, slates, roofers, or timber battens. You can also use ridge tiles to go for a drier system.

After completion, add skylights or roof lights to make it attractive. You can always make the inner of the roof a mini store room by installing a bi-fold door. In this case, you will get extra space for storage on the ground floor with the help of a simple bi-fold door.

a garage with piched roof extension

These days pitched roofs are considered to be part of the classical aesthetics for houses. It was already popular for its use in humid and snowy areas, but now there is a trend of these houses nearly everywhere.

If you want to make your house roof pitched DIY style, then with our extensive guide, you do not have to go to an architect or an engineer for the roof. Follow the workable guidelines and feel like an artist by building your roof. 

Do not forget to consider the building regs of your area while completing the process for your home extension. This should be permitted development to keep you safe from any inconvenience. 

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