Guest User
7/28/2001
I have a log house that my father built in 1978. It has a 6" beam construction overlayed with 2x6" tongue and groove. On top of that is 4" foam core insulation with paper and shingles finishing it off. The insulation has gotten semi-soft in areas around the skylights and the shingles break if any pressure is put on them. Everytime I go up to repair a leak I create more, in different areas. I would like to go with a metal roof. My thought was to go up the roof every few feet and screw 1x4's through the insulation and shingles into the 2x6's. The new metal roof would be affixed to the 1x4's. What are your thoughts on this?
Todd Miller
Classic Products, Inc.
7/30/2001
Some metal roofs would be appropriate for fastening to the 1 x 4's. Other metal roofs require solid decking beneath them. Once you choose the style of roof you'd like, I'd suggest contacting the manufacturer in order to discuss the installation in detail. The construction method on your home is something that was done back in the 1970s. I really am not so sure it's being done today. The insulation ages, as you have experienced. Really, depending upon its condition, I have to wonder whether it is at all suitable for being left in place. It sounds like there is probably no ventilation inside the structure. What concerns me is how you're avoding excessive moisture build-up in the house without any ventilation. Moisture is created in a house by many sources. Typically, that moisture rises and condenses on a cool surface unless it is exhausted out through ventilation. It is possible that moisture from inside the home is getting up into the insulation and is part of the reason for its degradation. If you add a new roof on top of that, the situation could be worsened by further trapping that moisture. One thing you might consider would be adding an airspace on top of the insulation (perhaps first replace the insulation if it's in real bad shape) and providing venting from the eave soffit up through a new ridge vent installed with the new roof. I'd suggest removing the old shingles before doing this, just to enhance the breathability of the structure. This airspace could be topped with either purlins (lathe) and then the metal panels (if you choose a metal product that is appropriate for this) or by solid decking and then the new roof. This airspace will help with moisture ventilation as well as with reducing summer heat build-up. It can also help prevent ice damming if you're in a cold climate. If you do this, make sure that your fasteners reach down to the 2 x 6s. You might consider stainless steel screws for maximum durability.
Guest User
9/30/2001
My mother has a metal roof on her home which is about 3 years old. The metal shop across the highway has brought it to our attention that there is "white rust" on her roof. My husband said this was caused by rain standing on the roof material before it was installed....Is this true or what would cause this problem?
Guest User
9/30/2001
My mother has a metal roof on her home which is about 3 years old. The metal shop across the highway has brought it to our attention that there is "white rust" on her roof. My husband said this was caused by rain standing on the roof material before it was installed....Is this true or what would cause this problem?
Allan Reid
Dura-Loc Roofing Systems, Inc.
10/2/2001
Most asphalt roofs self destruct in this application from the build up of heat and generally speaking you are on the right train of thought by roofing over with a metal system and there are a number of batten mounted system that will work. There are a few concerns and one needs more information to make a better recommendation. It would be good to know the roof slope, ceiling height, geographic location and type of insulation. One should investigate to see if there was an air barrier place directly over the 2x6 deck. This is instrumental in keeping the warm moist air from passing through to the outside and condensating in the assembly somewhere. Next there were a few types of rigid insulation used around that era that would lose their properties and degrade over time if subjected to continuous moisture. There are many metal roof systems on the market that are tested to be installed in the manner you mentioned however one needs to be sure that you identify and cure the problems and not just treat the symtoms when you replace the roof. The new building codes call for a minimum air space of around 1 1/2" which is to be ventilated and your new assembly should incorportate this.I would reccommend taking a test cut on the deck in an out of the way place to investigate the assembly and possibly have the insulation material identified.Once you chose a manufacturer they should be able to help in this regard, Good luck.
Allan Reid
Dura-Loc Roofing Systems, Inc.
10/2/2001
The common substrates of metal roofing at Galvanized or Galvalume Steel, Aluminum, Copper and Zinc. Either of the above metalic coated steel products contain zinc in the caoting as a rust protector. Metalic coated metal roofing is at its most vulnerable in the pile prior to installation. If it becomes wet you have water, oxygen and zinc which acts like a battery in that it starts up an electolitic action. Heat can accelerate this process. It is identified by a white powder or stain on the product. I would suggest that you contract the contractor and the product manufacturer to investigate and confirm if this is the case.
Allan Reid
Dura-Loc Roofing Systems, Inc.
10/2/2001
The common substrates of metal roofing at Galvanized or Galvalume Steel, Aluminum, Copper and Zinc. Either of the above metalic coated steel products contain zinc in the caoting as a rust protector. Metalic coated metal roofing is at its most vulnerable in the pile prior to installation. If it becomes wet you have water, oxygen and zinc which acts like a battery in that it starts up an electolitic action. Heat can accelerate this process. It is identified by a white powder or stain on the product. I would suggest that you contract the contractor and the product manufacturer to investigate and confirm if this is the case.
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