In This Article:
Bad shingles are removed down to a row of good shingles. Holes in the roof sheathing are filled and new shingles are installed.
2-3 (Basic To Intermediate)
About 30 Minutes
Bruce W. Maki, Editor
This article describes the process of patching holes in roof sheathing and fixing the shingles. This repair was done to fill in the holes after two chimney vents were removed, but the procedure shown could also be followed to patch a hole in an asphalt shingle roof that was damaged by other means, such as a tree branch that hit the roof during a storm.
The roof, after both vents were removed. (Read about removing the chimney vents.)
The shingle I'm pointing at (with the pry bar) is the highest level that needs to be removed...
... but first I have to remove the nails holding the shingle above.
Why? When shingles are installed properly, the nails in each row will pierce the very top of the shingle below. That way, almost every shingle has eight nails holding it down.
I used the pry bar to lift the shingle tab and expose the nails.
I used the flat pry bar to prop up the tab, and the bent mechanic's pry bar to get under the nail head.
The bent pry bar is very effective at removing roofing nails, at least part way.
Then I used the flat bar to pull the nail out.
Instead of removing the entire shingle, I just cut out the bad tabs with a pair of tin snips.
The shingle just slid out
The entire top row of bad shingles has been removed (between the red arrows), exposing the darker material underneath.
All of the damaged shingles have been removed.
Note the "stair-step" layout of the shingles left behind, as illustrated by arrows 1, 2, and 3.
Note the end of row 4... if I had cut out one more shingle tab, the ends of all four rows would've formed a perfect stair-step pattern. But there was no reason to remove that last tab.
I inserted a long board (About 3 times longer than the hole diameter) into the hole and held it up while I drove in some deck screws.
Then I installed a circular cut-out to fill the hole. I used a jig saw to cut the disc.
The method I show above is suitable for small holes, perhaps 6 inches across or smaller.
For larger holes, I prefer to cut the roof sheathing back to the rafters or trusses, and fill in the opening with a piece of plywood or OSB the same thickness as the rest of the roof sheathing. Such a patch should be supported along the full length of each edge. Support for the top and bottom could be provided by attaching pieces of 2x4 between the rafters (and fastened to the rafters) and then fastening a cleat (a block of wood) to each rafter along the sides of the opening.
It's important that any patch in the roof sheathing be supported on all sides because if a person steps on the edge of an unsupported patch, the plywood will flex and the roof shingle will get torn, which will leak unless repaired.
I attached a piece of tar paper (roofing felt) to the work area, tucking it under the upper shingles.
Then I went to work installing shingles.
I put a dab of roofing tar on each nail head, and along the adhesive strip, just to make sure the shingles stuck together properly.
Before you hurt yourself, read our disclaimer.
At this point, only one more row needed to be done (between the red arrows).
Installing the shingles up to this point was easy, just like doing a new roof.
I used the flat bar as a prop and drove the nails in.
Then I applied some roofing tar.
The completed patch. If done correctly, you should not be able to see the patch work.
Working on a roof is perhaps the most dangerous aspect of home improvement. A fall from even 8 or 10 feet can be fatal, or render a person paralyzed.
Working on the edge of a roof is best done from a ladder or scaffolding. Leaning over the edge of a roof, while on the roof, is very dangerous.
The roof slope, measured as units of rise per 12 units of horizontal run, can make a big difference in what safety equipment is needed. The roof in this article had a low pitch of 3:12, meaning that the roof rose 3" in 12" of horizontal travel.
I have worked on a lot of roofs with a 4:12 pitch, and I believe they are quite safe when the weather is dry and not windy. I have also climbed up roofs with a 9:12 pitch and almost fallen off. Certainly a roof with a 9:12 pitch or steeper requires roof jacks and planks to be adequately safe. Roof jacks are metal brackets that are nailed into the roof sheathing and/or rafters, to which 2x8 or 2x10 boards are affixed. The boards become stable surfaces to walk on. Several rows of roof jacks and planks are typically needed. A steep roof may require a dozen or more roof jacks to safely work on any face.
Even a roof with a slope of 6:12 is steep enough to fall off. I recommend setting up a row of roof jacks and planks at the lower edge.
In general, any person who is planning to work on a roof should consult someone with a lot of experience, if they are uncertain of their own abilities.
In no way will this author, or HammerZone.com, be responsible for any injuries or damages incurred by any person who follows any procedures shown on this web site.
Read our Disclaimer.