Reroofing might be a good choice when your roof condition is good despite starting to fall off. Reroofing is a rat’s nest of troubles and leaks. Generally, the new roof stays higher than the existing roof, and in order to complete the task efficiently, you will need to hire a pro.
Adding a new roof is diligence and hours of hard work. According to DIY, tying the additional roof to the existing one is the best option in this case. The process may seem complicated, but it differs from what one might think.
Continue reading to know the reason and step-by-step guide to the addition roof higher than existing roof.
Why Is the Addition Roof Higher than Existing Roof?
Adding a new roof over an existing roof is known as reroofing. Roofers install a new roof over the existing one in this process. For example, roofers add a level of shingles, meaning tearing off the old roof is not required. Remember that the process can be done once since your roof can only have 2 levels of shingles.
The new roof is usually designed higher than the current one. The prime reason is to enhance the drainage system.
Also, reroofing protects your home from numerous environmental damages, named water damage, hail, tornadoes, heavy snowstorms, etc.
More importantly, it prevents minor roofing problems from developing into significant ones. Overall, reroofing enhances your roof look.
Reroofing comes in different designs and colors. You can choose the design and colors according to your preference. However, the new roof will always stay higher than the current one. By installing a new layer of shingles, your home will get a 3-dimensional appearance.
How to Tie Addition Roof Higher than Existing Roof?
Before tying a roof to an existing roof, you will need to understand a few construction terminologies related to the method.
The key terms are described below:
- Ridge: It is a horizontal beam found in the rooftop connecting 2 roof planes.
- Rafters: These are sloped beams. They are connected from the wall plate to the ridge. The rafters support shingles on the roof.
- Wall Plate: This is a horizontal lumbar supporting the rafters.
- Truss: The roof layout is formed by the truss or roof frame. It consists of several beams. Nodes connect the beams.
- Valley: It is the intersection where 2 sloping roofs connect and permit continuous flow of water off the roof.
- Eave: This is a part of the roof hanging over the walls of a house.
- Jack Rafters: These are short spars running from a valley to the ridge or an eave to the hip.
- Run Length: Distance from the wall and the ridge.
- Snapping Lines & Chalk Lines: A string containing chalk to mark straight lines on an imbalanced surface.
Follow the step-by-step guide below,
Step 01: Framing the Roof
Take the rafters or trusses up on the additional roof. Match them up with the current roof’s eaves. Use chalk for marking the shingles. The marks will indicate the position where the new valley is installed.
Removing the shingles in the marked area would be best. The reason is the new roof will cover this area. You can strip the old shingles according to your preference. But remove them if the condition of the old shingles is bad.
Step 02: Valley Board Installing
Next, place a valley board over the current roof. Before doing so, calculating the roof pitch is crucial. This is the existing roof’s slope.
First, begin by measuring the length between the rise of the roof and wall and the ridge. Then determine the angle using a calculator.
After nailing down the alley boards, apply roofing cement on the nails. Also, remember to put cement on the outer edges where the valley board and the existing roof meet. This way, leaks will not occur over time in those areas.
Step 03: Underlayment & Sheathing
Then, the plywood sheathing needs to be installed on the new valley board using nails. Choose the correct-sized nails. Otherwise, proper penetration will not happen, and the valley board and the plywood will be damaged.
Remember to keep a 1/8” gap between every piece of the sheathing. Use the nails 6” apart and roughly 3/8” from the plywood sheathing edges.
Once the sheathing is secured, make the sheathing water-resistant by laying waterproof underlayment.
You can also check out the roof sheathing thickness code for a clearer concept.
Step 04: Shingles Near the Valley Board Needs Removal
It is vital to lay down a snapping line 2” from the old shingles valley board. Next, the shingles need to be stripped. Finally, lay additional waterproof underlayment on the area.
Step 05: Tie Current Roof Shingles
Begin removing the new valley’s 2 shingles from both sides and continue until you reach the bottom. Mark them with numbers, as they will be beneficial later. Keep them aside.
Then, lay shingles on the roof’s edges. Proper spacing is vital when doing so. For this, use snapping lines. The shingles should touch the surface minimum of 1 ft. in the area where the current roof and the new valley connect.
After that, reinstall the numbered shingles. Last, apply 2” wide roofing cement up to 4” from the valley’s center to secure the shingles.
According to Martin from Green Building Advisor,
“Keep a bundle of cedar shingles handy to use as shims — you’ll need them. It’s hard to avoid lips and bumps. For a subtle shim, you can use asphalt felt, folded multiple times as needed.”
Frequently Asked Questions (FAQs)
What is the cost of an additional roof over an existing roof?
The cost depends on a few factors, such as the roof size, the number of shingles, etc.
As per Fixr, you will have to spend $50 – $450/truss. The required tools and materials also need to be purchased for the project’s completion.
What do I need to remember when tying a new roof to the current roof?
Tying the new roof to the current one is a complex process. It will cause different problems if you don’t remember the below points,
*Water damage will happen to the construction of your home if you don’t tie the additional roof to the current roof.
*Don’t damage your new or old structure by putting excess weight on the additional roof. In this case, take assistance from an engineer to know the permissible weight of the additional roof.
*Serious injury can happen at any time when installing a new roof. Take necessary precautions to confirm a safer working environment.
Should I use staples or nails in the process?
Both options are helpful for different purposes. Staples are an excellent choice for plywood sheathing. On the other hand, shingles can be secured perfectly using nails.
Hopefully, now you know addition roof higher than existing roof is not an error or design flaw.
Reroofing will be a great choice if you don’t want to replace your roof. Also, it saves valuable time and money since the old roof doesn’t require a complete tear-off.
Note that adding a new roof is challenging, and everyone can’t do it. It would always be best to ask for help from a professional roofer to complete the job perfectly. They will inspect your existing roof and give you a piece of advice regarding the best option.
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