It is possible to install metal roofing over old sheets without tearing them off if the local construction regulation allows it. Although removal of the old roof is the preferred course of action, removal is untidy and raises the expense of the activity. Metal roofing is a lifetime investment that can last for 50 years or more if it’s a decent one. The average life span of Asphalt roofs is around 20 to 30 years, depending on the installation and quality of the shingle. A potential issue with this sort of installation is trapped water vapor. Whenever water vapor is trapped between the metal roofing and old roofing, moisture can accumulate and create mold and rot. Be it as it may, roofers can install a vented metal roof that mitigates this potential issue. Or on the other hand, installing the new metal roofing over furring strips might raise the metal and cause a ventilating air pocket between layers.
Covering house with metal roofing over an old roof in Milton
Preparatory stage:
Determine the Condition of the Old Coating
The integrity of the existing roof, including rust, rot, holes, its insulation, and furthermore, its ability to support and transfer concentrated loads and extra shear loads to the underlying structural must all be put into consideration. The old roof needs to be inspected for any damage, and necessary repairs should be made, all warped or loose roofing material should be secured, every protruding object that can damage the new roofs must be eliminated, any form of debris must be removed from the roof and all overhanging roofing must be cut off so that it flushes with the roof deck.
Check ventilation system status
Ventilation, which is the exchange of air, in, around, and all through the roofing system, needs to be properly checked to ensure its effectiveness. Proper ventilation of the roof is very important for meeting the design specifications of the roof, as well as maintaining and ensuring a long life to the roofing system. Ventilation is very important to a metal roofing system in order to limit the effects of condensation
Take Measurements and Count the Necessary Material
The most significant thing about installing a metal roof is to measure the roof accurately without error. The reason for this is that each standing seam panel is cut to the exact size, and if your panels are short, you will run into extra work and will likely have to spend a lot more money compared to what should have initially been spent.
Features of metal roofing installation on top of an old roof
Features of The Old Roof
If you notice bald spots on your roof, water leakage, cracked shingles, or shingles make your house look old, you need a new roof. In a situation where you already have more than two layers of existing roofing material, adding a third layer, even a metal one, is a bad idea. In this situation, you will probably need to remove the existing roofing materials.
Roof Pitch
Roof pitch, or slope, is an essential factor to consider, but the field measurement of this roof parameter will ensure an accurate estimation of important material and supplies. This can be determined using various methods. One of the methods requires taking a few simple measurements and either calculating or using a table to determine the slope or pitch. Another method uses a simple slope measurement tool. This is basically a protractor-type apparatus, which is placed on the roof slope and directly read off the dial.
Condition of Rafters and Insulation
Rafters are the sloping timbers that make up the roof itself. A common way to insulate your rafters is to fit the insulation between and over them. This is a common practice in reroofing situations. The use of rigid insulation board, carefully cut to size can be employed, or spraying of foam insulation between the rafters can also be employed.
Gutter System
Gutters are the flat metal portions of the system, which is mostly aluminum. They are usually installed along the eave edges of your roof, or along with roof features like dormers. Gutters are open at the top to trap flowing rainwater off the roof and directing it into the downspouts. Downspouts are the vertical, closed segment of the gutter system that directs the water from the roof to ground level. The drainage system guides the water away from your building’s foundation.
Benefits from installation metal roof over an old roof
– One of the benefits of choosing to install a metal rooftop over an existing roof is that the existing roof surface can normally remain in place. This saves many hours of labor and the cost of demolition of the existing roof. It also cost-effective when compared to other roofs because it can last for multiple decades.
– Another benefit is that the old roof’s coat can provide an extra layer of insulation to the roofing system. It serves as additional insulation against harsh weather conditions. Also, installation work can be done without exposing the interior of the building.