Installing metal roofing

Important note: do not attempt this on a building that you cannot freely walk on because of the pitch, or angle of the roof. If the building is VERY steep have a professional roofing company do the work

You have a garage or tool shed that needs the roof replaced. You have heard that a metal roof is economical and lasts for years once it is installed. But the bids on having a professional make you wonder if you could do it yourself.

And use the money you save for a new deck, or even to buy something you have put off.

First, you will need the proper tools and materials. These include:

Measuring tape

A good drill with three different bits: a ¼ inch screw head bit; a 5/16 screw head bit; and a standard Phillip’s bit.

A chalk line with plenty of orange chalk

A good extension ladder and a step ladder

½ pound of 1 ¼ inch roofing nails and a good hammer

Metal roofing screws: ¼ inch wood screws and 5/16 inch metal lap screws

Ten pounds of Phillip head screws ( 3 inches long)

Metal cutting “Snips” (look like big scissors with a straight edge; you can buy them at any large hardware store)

A cloth nail bag you can wear and put the screws in while you work

To decide how much metal roofing you will need, measure the height of your roof and add whatever overhang you want (anywhere from two to four inches is usual).

Also, measure along the length of your roof and the height on both sides to decide how much metal edging you will need. This will go all the way around the edges of your roof.

Take the measurements of the height and length of your roof to your local roofing supply house. They will help you to order the metal sheets and edging in the correct quantities.

Be sure to include room for 3-6 inches of unblocked air flow between each layer.

There are two basic types of metal roofing that are commonly used that a homeowner can install. These are:

R-panel metal roofing: This is a panel type sheet that has high ridges ; this uses 5/16 lap screws to install

V-crimp roofing: This type of roofing does not need lap screws to put on, and is the simplest type to put up.

It is always best to take off the old shingles if possible before starting to install new roofing. You can “tear off” composite shingles with a pitchfork or a roofing shovel. You will then put down 30 pound tar paper, or roofing felt, as a base for your new roof.

If there is only one layer of shingles on the building, you can also choose to put down what is called “slat board”. This is 1x4xlength of building pine wood boards that are screwed down over the old roofing with the 3 inch Phillip’s screws. They should be placed every two feet lengthwise measuring up from the bottom of the roof up. You can then put the new metal roof on over these boards.

Now you are ready to start putting on your metal roof. Put your metal edging down; it will run all around the perimeter of the roof. You can nail this in with 1 ¼ inch roofing nails.

If your metal sheets are longer than 12 feet, you will need a second person to help you carry the sheets up onto the roof (they get quite awkward to handle!). If they are less than 12 feet, just lean them up against the building where you can reach them and you can pull them up as needed. If you are right handed, start on the right hand of your building.(if you are left handed, start on the left side of the roof). The sheet will run from top to bottom and cover one section of the roof like this:

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I I

I I

I I

I I

I I

I I

______________________________________________________I_______I

^

One metal sheet

Use the ¼ inch metal wood screws and screw the roofing into the wood slats or else pop a straight chalk line every two feet across the length. These will be your guides because you will be putting in wood screws every two feet on both sides

The exception is the first sheet: you put the screws on every two feet in the CENTER of the sheet and the inside edge of the sheet (you don’t want to screw into the metal edging on the outside edge. You will be putting on trim edging to cover the far side).

Your next sheet will overlap the first sheet. If it is V-crimp, one dip or crimp in the sheet above will overlap one crimp in the sheet beneath.

If the roofing is R-panel, one ridge or lip will overlap a ridge in the one already screwed in.

Do the same thing all the way across the roof until you get to your last sheet. On the last sheet, measure the amount of extra space left over past the roof edge. Now, mark the row or ridge that is just PAST the edge of the roof. Then, take your tin snips and cut along this row all the way down. Screw in this last sheet.

Now, go to the other side of the building and do the same thing.

After getting the sheets down on both sides of the building, go back and put in lap screws if it is R-panel. The 5/16 lap screws are used and go in every four feet at the point where two metal sheets overlap (this is called the “lap” by roofers).

Now the metal trim goes on. It will cover the sides of the roof at the edge. It will also cover the ridge of the roof (the top peak) as well. You have to notch it in the middle so you can bend it over the ridge of the roof.

/\

/ \

/ \ Metal trim is notched in center so that it will bend over

// \\ the ridge. It will cover the WHOLE edge on both

sides of the roof.

The metal trim is screwed in with ¼ inch metal wood screws every two feet.

If you are working with R-panel, you will now need to put in your closures. These are pieces of foam rubber that come in 3 foot lengths that follow the design of the R-panel holes. You push it up into the openings along the edge (it prevents birds and animals from going up inside the ridges). It has a glue at the bottom and will self seal and stick when put in.

Now, screw the bottom of your sheets down (don’t do this before putting the closure in!). V-crimp will not have foam enclosures and you can screw down the bottom any time while putting the sheets on.

Now you will do the ridge. With R-panel, it will come with a foam enclosure similar to your bottom enclosures, but this will fill in the wide gaps at the top of your sheets. Place these on top of the sheets at the ridge (top of the roof) to fill in the gaps. Next, take the special metal ridge for either R-panel or V-crimp and screw it onto the ridge with a screw on either side at the point where the high point of a R occurs (with R-panel) and put it in with a 5/16 metal lap screw. Do this every two feet on both sides of the ridge.

With V-crimp, use the ¼ inch metal wood screws on each side close to the high point (but not on the very highest point) of the Vs. Do this every two feet on each side.

Now you are done, and you can sit back and admire your handywork and the money that you saved.

Copyright 2000 by Sheri Waldrop