Home is everyone’s dream object, and nothing is important like home. When you’ve found your dream house that fits your housing budget, the desire to purchase it will be inevitable.
However, after purchasing your dream house, you might realize that the roof design requires special attention, particularly if you plan to renovate or expand. As a roofing professional with over a decade of experience, I’ve encountered various scenarios where homeowners must join roofs of different pitches.
One key challenge is ensuring a seamless transition between the different slopes, which, if done incorrectly, can lead to water leakage and structural issues.
Read also : How to Install Drip Edge on a Metal Roof
Now, what to do? Searching for the answers on the net can be helpful. So, get ready to jot down the steps of fixing your roofs with different pitches.
How To Joining Two Roofs with Different Pitches
If you’re new to this, don’t worry. Here’s a guide to help you through the process, including how to prepare the area and measure the length of the joined area. The pitch itself is a ratio of the roof’s rise and span. It is commonly shown as a fraction number like 5/12, 10/12, etc.
The higher the numerator, the steeper the roof will be. This becomes particularly significant when joining two roofs, as precise alignment is crucial for structural integrity.
For example, when working on a project where the roof pitch difference was significant, we had to carefully design the intersection to prevent water from pooling at the joint. Here’s what you need to join two roofs of different heights:
- Working gloves
- Measuring tape
- Permanent marker
- Screwdriver
- Circular saw
- Metal snips
- Metal screws
- 2-by-4 and 1-by-1 lumber
- Butyl caulking
- 12-inch aluminium flashing
- Shingle
- Shingle remover
- Saw
- Roofing nails
- Underlayments
- Metal snips
Read also: How to Build a Pitched Roof On a Pergola
Procedure for Joining Two Roofs
- First, identify the areas of the existing roof that you want to join. After putting on your gloves, remove the shingles and underlayments on both edges to a width of about 6-8 inches.
- Next, measure the length of the joined area and add 12 inches to this measurement for your flashing material. This extra length ensures adequate coverage for the joint.
- Cut down the flashing after matching it with the measurement using your metal snips.
- Common rafters might require adjustment as you place the flashing between the two roof pitches. Start by sliding the flashing under the higher pitch, then the lower. To bend the flashing, gently press a 2-by-4 until it matches the slopes. Set the lumber aside.
- For the next step, you need to measure, mark, and cut two pieces of 1-by-1 lumber to work as the edges seals. Just like what you do with the flashing, slide the first piece under the higher roof first, then place the second piece under the lower roof.
- Keep 1-by-1 lumber pieces in their place, and add some butyl caulker. Let it dry.
- Now, stick the flashing to the roof using metal screws along its four sides. Each screw is spaced around 6 inches. Measure and add it by 1 inch, then cut a piece of underlayment. Slide the underlayment beneath the still-existing shingles and secure the underlayment by nailing it using roofing nails.
- Make it neat by folding the flashing edges around the roof’s edges and along the eave’s bottom. Attach the folds using metal screws. Before joining two roofs, you can temporarily remove the eaves’ trim and replace it after joining the roofs.
- After securely joining the two roofs, it’s important to cover the flashing with shingles, ensuring they overlap properly for full coverage. I recommend using high-quality underlayment beneath the shingles, as this extra layer protects against leaks, especially in areas where the pitch difference is noticeable.
- In a recent project, we used a synthetic underlayment that significantly improved water resistance at the roof joint. With these steps, your existing roof will have a new, unified appearance.
| Task | Recommendation | Reason |
|---|---|---|
| Measuring Joint Area | Add 12 inches to the flashing length. | Ensures sufficient coverage and protection. |
| Placing Flashing | Start with the higher pitch and overlap with the lower pitch. | Prevents water infiltration at the joint. |
| Securing Lumber | Use butyl caulking and ensure it’s dry before proceeding. | Creates a waterproof seal, preventing leaks. |
| Covering Flashing | Use high-quality underlayment and shingles with proper overlap. | Enhances durability and protection against weather elements. |
Roof work involves risks due to height and uneven surfaces. It’s wise to conduct multiple surveys and practice sessions before joining two roofs with different pitches. This preparation helps you become familiar with the roofing surface and ensures safer working conditions.
That way, you can get used to walking on the roofing surface and adapt well to work in such a condition. Always use gloves and goggles to keep yourself safe.
Roof work involves certain risks due to height and potential uneven surfaces. Conduct multiple surveys and practice walking on the roof to become familiar with the conditions, enhancing safety. Always wear gloves and goggles for protection.
Following these steps and ensuring precise cuts and secure installations, particularly at the plumb cut and rafter tail, will ensure that your roof looks unified and stands strong against the elements.
