Q&A for How to Install Metal Roofing

When it comes to roofing, it's very important that you know what you are doing. The task requires a great amount of workmanship. If you aren't sure, consider hiring a professional.

The fascia should remain in place. The eaves are below the fascia, and shouldn't be in the way.

This will not work, the layout never lines up. You will need to add slats of wood perpendicular to accommodate the layout.

Use a synthetic type of paper over the black felt. This will allow the area to breathe since there will be that space created.

This would be possible, just make sure and use the right type of roof screw and make sure its long enough to enter the wood substrate.

Most states allow up to three layer of shingles, so you should be OK. Check with the local building department. The shingles may create uneven areas for the metal and not suitable. These areas may have to remove shingles (valley and ridge locations).

The recommended slope for metal roofs is 4:12.

Metal roofing can be installed to any roof type that is not flat. The look is totally different, the sound is noticeable, metal would last longer than asphalt shingles.

This is not common, but can work. You want to be sure the sheet metal has venting or a hole to cover with a screen. If you get some J-style molding, this would cap off the metal nicely.

A standard minimum for a sheet of metal placed on the roof so that it overhangs the edge is at least ¾ of an inch to 1 inch (2-2.5cm). On the other hand, a maximum is around 8-11 inches (20-30cm); if it's longer than this, external supports are usually required. However, the length permissible will vary depending on whether the overhang has been stiffened or unstiffened and the type of metal roofing being used. Always consult the manual for your roofing type; if you didn’t get one, check the manufacturer's specifications online, as reputable products will usually come with a manual on the manufacturer’s website.

It may be possible to install a metal roof over shingles but this must be permitted by the local building code in your area, so check that first. It’s also a good idea to discuss the options with your roofing contractor because they will be able to check the type of shingles your roof has and advise on the suitability of leaving the shingles in place or removing them; one common problem is moisture build-up between two layers of roof type, which must be avoided. Often, it is best to remove the shingles but it can make the job more expensive.

The type of underlayment often placed under metal roofing is made from felt that has been treated with asphalt. Although this is a traditional form of underlayment, there are other types of underlayment made from synthetics (such as polypropylene or polyethylene mixed with a polymer). Each type has advantages and disadvantages that depend on the type of roof you have and your local climate, so you’ll need to do research into what's best for your environment and roof. Also be aware that not all roofing needs underlayment; for example, it's not needed with open beam with structural metal panels. So, be sure discuss this with your roofing contractor or supplier.

The cost for metal roofing will depend on the size of your roof, your location, and the type of metal roofing you’re seeking to install. A ballpark figure for an average sized house roof would be anywhere around $4,000-$17,000 but the actual cost really does depend on the factors previously listed.

For a roof with no decking, yes.

No, you can install steel roofing directly on purlins. This is typical in storage and agricultural buildings where it is more cost effective. Use sheeting or decking on living spaces.

Any large building supply company will either have standard lengths in stock or have the ability to order it for you. All you need to do is figure out your length and color.

Some people do it differently. It makes more sense to put them in the ridges because the water's going to run down into flat surfaces.

Yes. All you have to do is run 2x4 material across the roof so you have something to screw the metal into.

The side without the lip, but rather a groove, will be the side that overlaps.

Find a metal supermarket near you, they can fabricate a metal box for the base depending on how it needs to incorporate into the rest of the roof.

Yes, a metal roof can have a ridge vent. There are a couple ways of doing it. You can use a roll of ridge ventilation and roll it out as you would with asphalt shingles, putting the ridge cap on top of that and screwing it down. Or, for a cleaner look, you can use a special type of bracket that's made specifically for metal roofs that your ridge cap will screw into.

If the old roofing is damaged, you should remove it to check the condition of the under layer.

Yes, the screw heads will be proud (slightly projecting from the surface) of the material. This is why many companies will offer matched-color screws.

I had a metal roof installed over semi-wet 3-tab shingles. As long as proper ventilation is maintained, the shingles will dry quick enough so no problems should occur.

By installing a saddle flashing that goes above the lower panels and beneath the upper panels. This of course also depends on how great the pitch is. Think of a roof to wall situation; it's the same basic concept.

If you had vents for your furnace and toilets, you still definitely need roof vents for your furnace and toilets. It is dangerous if they are cut off and sealed in the roof.

Yes. The warranty in most cases is only on the the paint. Some metals have warranties, but only if you follow their guidelines.

No if the screws are installed properly and the grommets aren't over tightened, they will last as long as the roofing.

Typically $50 per sqft if you have someone do it, but as little as $13 per sqft if you do it yourself.

Take photos of the final look and the problem areas. Check the contract terms and conditions and ask them to return to see and follow up your concerns. If they offer to redo it, that's great. If they don't, or you don't trust them, then ask for a refund. If this fails, contact your local consumer affairs for advice. Then, talk to a lawyer. If you take them to a small claims court and request a judgment in your favor, this requires a lot of preparation and good organization of all the evidence you've gathered together, along with some expert advice supporting your case.