Building specialists are always looking for installation techniques that will offer them with financial savings on labor and products expenditures. Here are some crucial solution to frequently asked questions.
1. Should I set up a steel roof straight over-top of an asphalt tile roofing system? No. Why?
Premature Failure: Steel has a high degree of thermal growth and also tightening. As the roof covering warms up and cools off, it moves along both its size and its size. Put straight against the granules on asphalt shingle, this activity will scrape the below of the panel and also ultimately reveal the bare steel, hence possibly creating early failure i.e. rust.
Voided Service warranty: The installation of a metal panel directly over top of a rough product, in many cases, spaces the maker’s rust service warranty (this would relate to Galvalume panel just as galvanized steel does not bring a corrosion service warranty).
Shape: The panel will certainly take the form of the underlying irregular surface area and, in many cases, make form problems noticeable that were formerly concealed.
2. What happens if I put down an underlayment before placing the metal roof covering on?
This is absolutely a better choice, yet you will certainly still have the exact same concerns with respect to Forming (see above) and, needs to the underlayment deteriorate or tear and also expose the metal to the asphalt tile, there exists the possibility for Premature Failure which would certainly result in a Voided Guarantee.
If it is made a decision that this is mosting likely to be the installation technique, advised underlayments would certainly be Elegance Tri-Flex as well as IKO RoofGard. They are unsusceptible dampness and very tear immune. MMR does NOT recommend using 15 # or 30 # roof covering felt (tar paper) for this application.
3. Does that mean I should be stripping all asphalt tile roof coverings before laying steel down? No. MMR advises the stripping of the existing asphalt shingles, nevertheless we recognize that time and also spending plan restrictions do not constantly comply. Here is the recommended finest technique for re-roofing over an asphalt tile roofing system:
Roof Deck: Examine the existing shingle roof covering to identify if it is suitable as an obstacle against condensation. Keep in mind that a steel roof will, to a certain degree, develop condensation on the underside of the panels. Those locations that show signs of previous water infiltration (underlying sheathing is soft or squishy) or damages (missing or weakened tiles) should be fixed accordingly and also provided water tight with the use of ice & water guard and a suitable sealant (if required).
Ridges & Completion: Eliminate the cap roof shingles to avoid having a hump. If leaving subjected with the danger of rain/ snow, cover with tarpaulin or roof covering underlayment.
Roof Covering Sides: Cut the looming asphalt tiles purge with the fascia/ rake boards. This will also get rid of the existing drip side. This enables you to install your eave/ rake trim true to your house with a clean, tight fit to the fascia boards. Learn more information on roof shingle replacement from this article.
Hips, Ridge & All Protrusions: 9 – 12 inches of size on all sides of using plywood, OSB or comparable decking (density to match various other lumber).
Valleys: 16 – 24 inches of width on either side using plywood, OSB or similar decking (density to match other lumber).
Gable & Eave Edges: 1″ X 3″ spruce firring or similar measurement light scale steel framing, held up from edge by” -” so that it does not kick the trim out.
Interior of Roof Covering Deck: 1″ X 3″ spruce firring or comparable dimension light gauge steel framing, set up flat approximately 16″ OC (usage every second course of roof shingles are your overview).
4. All of this seems like a great deal of work. Why do not I simply strip the roof covering? That is a legitimate comment and also lots of professionals/ house owners determine to do just that. Below are factors to consider for both alternatives:
Leave Existing Roof Covering In Position:
Pro: No requirement to pay for dump fees;.
Pro: No demand to pay for new roofing underlayment so long as existing roof covering is suitable as an obstacle against condensation;.
Pro: If utilizing firring, produces an air barrier in between the steel panel and the roofing system. This allows condensation that establishes on the bottom of the panel to dry out more quickly;.
Pro: If using firring, reduces thermal transfer to the underlying roofing deck as the metal panel is staying up off the asphalt tile;.
Pro: If utilizing firring, allows for an affordable leveling of the roof surface if needed;.
Pro: Reduces the problem positioned on landfills annually;.
Con: Does not enable a comprehensive inspection of the roof covering deck prior to setting up brand-new roof.;.
Disadvantage: Renders the installation of snow guards more difficult and potentially less secure;.
Neutral: Not accepted by all building ordinance (hurricane susceptible areas require installation to strong deck making use of particular UL-90 rated clips).
Get Rid Of Existing Roof:.
Pro: Allows you to evaluate the condition of the roofing deck and make fixings as needed;.
Pro: Provides for a smooth, flat roofing surface area on which to mount;.
Pro: Allows for the correct as well as comprehensive setup of an ice & water shield;.
Pro: Permits a solid and also consistent surface right into which snow guards can be secured if needed;.
Pro: Gives a solid surface area for all bolts;.
Disadvantage: Added expenses with dump & disposal charges;.
Con: Included expenses through new roofing system underlayment.