The two most common methods of TPO roof installation are mechanically fastened and adhered.
Mechanically fastened roofs are screwed through the seam and the insulation down to the structural deck with special barbed plates and #14 or #15 fasteners. This is a more cost effective method but doesn’t offer as much wind uplift performance.
We also install Rhinobond, another mechanically fastened system with a unique membrane plate that allows for heat-induction between the top of the rhinobond plates to the bottom of the TPO membrane using a specialized rhinobond machine. Thermoplastic single-ply membranes may be mechanically fastened via Rhinobond technology utilizing induction welding insulation plates as the form of membrane attachment.
Adhered roofs are chemically glued and maintain a smooth, flat surface flush with the insulation and substrate, which offers a higher wind uplift performance and a more aesthetically pleasing look. Adhered TPO roofing assemblies are on average more expensive than mechanically-fastened.
Ballasted roofs are single-ply membranes loose-laid over the substrate and/or insulation, and then secured by overburden (river rock, gravel, concrete pavers, green roofing, etc.). Although optional, this approach is unconventional as it defeats TPO roofing’s energy saving quality and can make it much more challenging to identify and find leaks.
These installation methods can provide manufacturer warranties ranging from 5 – 30 years. Please consult our roofing specialists to design the correct system for your property.
Like all single-ply membrane roofs, TPO is naturally more vulnerable to membrane punctures that can lead to leaks since there is only one layer of protection.
Thanks to its heat-welded components, repairing typical punctures is often as easy as cleaning the TPO membrane and heat welding a new piece of TPO over the area. That said, TPO roofing repairs require special equipment (i.e hand and robotic welders) and experienced roofers to be performed effectively.
There are 3 major types of TPO insulation, all different costs and R-values.
Polyisocyanurate, or polyiso, is the most common insulation type because it has the highest R-value per inch of insulation. In most cases polyiso is a great fit but because of its flammability, it may not be suitable for buildings with certain fire restrictions or combustible deck types such as wood (ex. Class A).
Expanded Polystyrene, or EPS, is a more cost-effective option with a lower R-value per inch of insulation, but does show to be a cost effective option when used in fully tapered insulation systems.
Extruded Polystyrene, or XPS, is defined by its blue, green, or pink color and falls in between polyiso and EPS for price and R-value.
Curious to know more about TPO? Check out our blog HERE for an even more in-depth look at what our TPO services provide.
