Sealing Metal Roof


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Old 10-18-06, 12:36 PM
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Sealing Metal Roof

My metal roof is not quite steep enough to allow the snow accumulation to drop off of it during the winter time. Throughout the year, the snow accumulates and ice dams occur. Where different sections of the roof meet, the accumulation of snow and ice has been pushing off the sealant material. I am not sure what material was used for the original installation, but it appears to be a "tar" material seam. What would this be and is it easy enough to repair on my own?

Also, due to the snow and ice build up, it has caused the breather pipe on the roof for the bathroom to break off below the roof line. Is this an easy repair?

Suggestions are very much appreaciated.

Thanks!
 
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Old 10-18-06, 04:09 PM
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Check attic for air leaks from below. Seal all gaps where warm air below can leak into attic. Ice dams are formed when snow and ice melt on warmer, upper section of roof and runs down to edge of roof where it freezes. Check insulation to see if it has recommended R value for your area. Make sure kitchen and bath exhaust fans are vented through the roof and not into attic. Make sure duct work is not leaky and is insulated. Make sure ceiling is airtight to prevent heat from entering attic. Make sure attic as adequate ventilation.

There are many types of metal roof coatings available. Roofing cement is often used for metal roof repairs. Urethane roofing cement is supposed to be better than plastic or asphalt cements because it is more resistant to UVB breakdown. Caulk seams and edges along the flashing with urethane roofing cement.

Replacing vent stack will not be an easy chore. It connects to the sewer line. This will require some digging.
 
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Old 10-18-06, 06:25 PM
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Fibered roof coatings help but are limitted on how much they will seal. IMO caulking the seams is best, even better if you can get the caulk under/into the seams. The different roof tars also work well but they often need redoing after various temp cycles.

The plumbing vent [if accessable] can be cut in the attic and another piece of the same size added to extend it back to the proper height. Be sure to seal where it goes thru the roof well.
 
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Old 10-18-06, 07:53 PM
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In addition to sealing around vent opening, you can install collar (boot or vent sleeve), which is a preformed flange placed over the vent pipe to seal the roofing above the vent pipe opening.
 
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Old 10-19-06, 05:14 PM
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Metal Roofing

I have worked on a number of metal roofs (North West Coast) and find it best to first identify the problem areas before providing a solution(s) which adequately addresses each solution avoiding the "bandaid" approach. In my view, there is no one single silver bullet that will solve these issues.

Some of the following issues exist in metal roofing:

Thermal load - leads to expansion of the substrate and potential for seams to open and or screws to pop up/out. Until recently this has been a natural unavoidable condition.

Heat transfer - Heat transfering into the attic and ultimately the living space. Again, until recently this has been a natural unavoidable condition. Bulk insulations have been used to slow heat transfer but they do not actually stop heat transfer. Heat is actually trapped right against the substrate, something you want to avoid in the warmer climates or summer months.

Water proofing - For various reasons as mentioned above the substrate can be compromised. Waterproofing needs to be done in conjunction with the solutions required to resolve the other issues. You will need to use a flexible product that works with the other products/solutions.

Corrosion - Even galvanized roofing will eventually rust. Once it starts it will continue unless you have an encapsulator product that will stop rust from further develloping. This is conditional depending on the severity of the rust. Once it's gone well, it's gone.

UV - the radiation from the sun can deteriorate virtually everything unless it has UV resistant protection. Rule of thumb, if it's black don't use it because it won't last.

Acid rain and other polutants - can also contribute to the deterioration of your roof. There are a number of products that will provide this type of protection.

Your venting/breather pipe should not be a problem if it is simply plastic and of course providing you have adequate space in the attic to get at it. You may have to replace the flashing piece around it. This could be rubber or metal.

I have been able to provide a 10 year warranty on existing metal roofs using such a 4 coat system which addresses all of the problem areas such as corrosion, waterproofing, insulating and UV/low maintenance finish. The end result is a roof coating "system" that provides a long term solution.
 
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Old 10-23-06, 08:01 AM
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Thank you everyone for your suggestions! My home is a double-wide with a vaulted ceiling throughout and it leaves no room for an attic. The home also has a septic system, so I am not sure if that provides any additional help to a resolution. My hope was to get on the roof this weekend for a better look at the specifics of the roof and to also evaluate the pipe better, but we are getting snow and I am not ready to start sliding off of that Hopefully I will still get an opportunity this month to take care of this.
 
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Old 10-23-06, 09:23 AM
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Didn't realize your home was a MH. Kool Seal [or any fibered roof coating] is the material of choice to coat the roof with. It is always best to use tar or caulking to seal any problem areas first. I assume it is an older MH with the almost flat roof or does it have 3/12 pitch?

Your septic system shouldn't be a concern unless you are piping a down spout into the drain field.

If you can get to the vent pipe inside you could cut it and then attach a new longer pipe inside. usually the vent pipes are inside the wall so that may not be a great solution. With a little luck you might be able to glue a smaller pipe into the vent pipe and then seal around that.
 
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Old 10-23-06, 12:05 PM
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The house is a '96 model and I believe it is the 3/12 pitch, it's not much of one for the weather that I live in.

I will have to see if there is anyway in the wall that could possibly help me with insatlling a new, much longer pipe.

Thanks for your help!
 
 

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