This article will focus on using Asphalt shingles, the most common and cost-effective solution, which is very common in the North East.
Here’s What You Need To Know
Now I will lay out the process and explain common problems that you should be prepared for and that should be addressed in the contract.
In some locations code allows you to put a second layer of Asphalt shingles on top of one old layer of shingles. More and more codes are no longer allowing this second layer. I would suggest you not put on a second layer as you have no way of telling if there are problems underneath (e.g., rotten wood). Another argument against laying additional layers of asphalt shingles is that the roofing materials can get too heavy for the underlying roof framing
I will assume you will not go the second layer route.
You ought to consider the condition of your gutter system before moving forward with the roof replacement. If they are in bad shape it makes sense to change them in connection with the roof replacement.
Most roofing contractors can install new gutters for you. If you’re going the replace the gutter system you might as well take them off first and get them out of the way.
The new gutter system will be installed after the new roof work is complete.
If the gutters are in good shape just make sure the Contractor protects them and keeps them clean while replacing the roof.
Okay, Let’s Put on A New Roof
The first step is removing the old Roofing materials.
This is usually fast as the roofers use various scraping tools to quickly remove the roofing material including the nails.
Generally, the scraping process does not remove every nail meaning after the old roof is removed it is usually necessary for the workers to go over the entire roof and use a tool to remove any nails left behind. A common and efficient tool for removing nails is a cats paw tool.
They also need to remove all flashing, drip edge, and collars around the plumbing stacks, because this should all be replaced.
Make sure and insist that your contractor lay out tarps to catch the derbies. These tarps need to be around the entire house from the roof edge to the ground to protect the siding and windows.
The contractor also needs to place tarps on the ground around ten to 15 feet out into the yard and on the driveway and any walkways. You must insist on this and here’s why. Once they start scraping off the old roof debris will fly all over the place. This includes Nails, roofing felt, pieces of old shingles and even pieces of rotten wood.
The nails are the biggest problem. If these are left in the yard you can hit it with your lawnmower and this can propel the nail like a bullet, very dangerous. Your contractor should also use a rolling magnet that can pick up nails that may fall off the tarps. They should run this tool over your yard, walkways and driveway before leaving to make sure no nails remain. You want to protect your siding, windows, and yard and this is all necessary
The contract may tell you they will rake it all up at the end, but this never works out like you want. It’s much easier to catch the debris with the tarps and then just through it all into the dumpster. Lack of clean up is a common complaint. Make sure you contractor has included the dumpster in the contract.
If you don’t have a Ridge Vent you ought to have the contractor install one on every ridge. This continuous vent along the peak of the roof will help air circulation in the attic space and can be integral in exhausting hot air and preventing winter ice dams (Ice dams are discussed later in this post). In order for a ridge vent to work properly you also need to have soffit vents. The soffit is the part of the roof that extends beyond the roof which is supported by a soffit joist. The underside of the soffit is then covered with wood so if you are looking up from the ground it looks like a ceiling. On or in connection to this small roof your contractor can install soffit vents
Samples of Soffit Vents
Small round vents the size of a hockey puck
The can also be long narrow vents that run the length of the soffit
These vents allow air to enter into the attic at its lowest level and the air then flows up and out the Ridge Vent Good circulation is key.
If Ridge vents aren’t practical, there should be other types of vents installed such as gable vents or a spinning turbine roof vent to provide air circulation in the attic space. And the exhausting of hot air.
When the contractor cuts the ridge vent they will be cutting into your roof at the ridge (Where the front and back roof meet at the highest point of the roof). Directly underneath the roof is your attic. You or the contractor should move anything stored in the attic away from this point and put a tarp down in the attic. Once they start cutting sawdust, and other debris will go right into your attic so get everything out of harms way and put the tarp down to make for easy cleanup.
Once the old roof materials have been removed the contractor should walk the roof and look for any damage (e.g., rotten wood) and make repairs as appropriate.
Theses repairs will add to the cost of the job but the repair should be made to ensure a long roof life. It is a good idea to ask your contractor to give a price to fix rotten wood based on square feet of repair. This price should be in the original contract so you are not having to negotiate in the middle of the project.
Pick Your Shingles
The roofing business uses some special terminology when estimating materials for a roofing job. The term square, when used in the roofing business, is a unit of area. One square equals 100 square feet. Shingles come in bundles. Three or four bundles of shingles typically will cover a square of roofing area. Work with you contractor in choosing your asphalt shingles. Do some research and consider manufacture warranty and life expectancy.
Ice & Water Shield Also Called Ice Dam Protection
Ice & Water Shield is a membrane made of a synthetic waterproof barrier material designed to prevent melting ice from backing up under the shingles and penetrating through the wood sheathing of your roof and possible enter your living space. This moisture can cause severe damage.
Grace Ice & Water Shield is a popular Ice & Water Shield Product. Do your homework and work with your contractor in making this decision.
Felt or Roofing Paper
Often the shingle manufacture will also offer a felt paper solution. Do your homework and work with your contractor in making this decision.
Install roofing paper over the roof sheathing. The layer of roofing paper creates an inner barrier against water penetrating into the house. Rows of roofing paper are overlapped as they progress upward toward the peak (the Ridge), and are normally tacked or stapled in place.
Drip Edge and Flashing
Apply metal drip edging around the edge of the roof, both the eave sides and gable sides. The metal drip edge is nailed in place over the roofing paper or Ice & Water Shield.
Drip edge is important. This metal flashing that is installed at the edges of the roof to help control the flow of water away from the fascia and to protect the underlying roofing components. Drip edge overhangs the sides of the roof and has a small metal flange that is bent away from the fascia.
There are several different other areas on your roof that need flashing. All of the old flashing should have been removed with the old roof. Always use new flashing to ensure a tight seal.
Roof flashing can be made of copper or rust- resistant metal—galvanized steel, aluminum, or and sometime rubber. I prefer Copper in most cases.
Where necessary, apply new valley flashing along areas where two roof planes meet. The valley flashing is typically nailed to the roofing deck and sealed with roofing caulk.
Flashing also needs to be installed around the chimney. In some situations, to properly flash your chimney and protect your roof you will need a small structure called a cricket. A cricket, or saddle, is a ridge structure designed to divert water on a roof around the high side of a chimney or the transition from one roof area to another and the cricket is normally the same pitch as the rest of the roof, but not always.
Flashing also needs to be installed around skylights.
Step flashing is necessary where the roof and a side wall meet as it protects from water leaks that can cause damage for years and you will not know because it hides itself behind the house siding.
Water vent pipe sealing. This pipe is necessary so your water goes down the drain in your home. With this your drains would not work right.
Remember when you were a kid you would put a straw into you drink it put you finger on top of the straw and when you put your thumb on top of the straw and took the stray out of the glass the liquid would not come out until took you thumb off the straw. Not having a vent pipe on your roof is like never taking your thumb off of the straw. The Shingles need to be carefully around the vent pipe as it is a Roof Penetration. You also need to install A Vent Flange Which Provides A Flexible and Water-Tight Seal Between the Roof And A Plumbing Vent Pipe.
Good luck with your roofing project. Steve