Cost, of course, can vary due to a lot of factors, like geographic location, and size and type of the project. Prices might be estimated anywhere between $3-$12 per square foot, and this can be effected by several other factors – the quality of the materials used, the labor costs to install these materials, and any associated warranty, contractor insurance, or bonding costs which will get passed on to the customer.
Initial Cost Factors:
- Roof Size: for example, large projects are often cheaper per square foot due to installation efficiencies gained with economies of scale.
- Roof Penetrations and obstructions: if your roof has a lot of obstructions – skylights, pipes, and AC equipment for example, you can expect higher installation costs due to increased labor requirements.
- Materials Used: EPDM and Single ply roofs are cheaper materials that won’t last as long. Higher quality roofing such as polyurethane foam may cost a little more, but it will insulate more efficiently and could last the life of the building. In contrast, a roof, such as Tar & Gravel, with insulation will expense about the same as an SPF roof.
- Location: Is your property in a convenient local location, or will your contractor’s crews have to drive a significant distance to reach your property?
- Condition of Existing Substrate & Roof: Can the current roof membrane be re-used, or does it need to be torn off? Is asbestos or other harmful substances under your roof membrane that have to be dealt with? Is there dry-rot or other failing materials. Do drains, vents, skylights or other roof penetrations need to be replaced or repaired?
- Are you thinking of installing solar power or replace your vents & drains, etc? It’s a lot more cost effective to do all of this at once. What if if your solar power installers caused a leak in your roof, and neither contractor (roofing or solar) wanted to fix the issue because they each blamed the other. If you’re thinking of installing solar, now would be a good time to coordinate the two installations simultaneously.
Long Term Considerations
If you’re going to install a roof, it’s good to think about the long term cost impact. If you have decided to install a foam roof, the insulation factor can pay off big in the long run. Also, think about adding cool roof coatings; just by changing the color of a roof to something reflective can lower summer cooling bills by 30% or more. Medium Density Sprayed Polyurethane Foam Roofing conforms to a roofs corners and angles and usually has an R-Value around 6 to 8 per inch of thickness. In layman’s terms, one inch of foam is as effective as 6 to 8 inches of solid wood.
In reality, due to things like vapor trapping (foam forms a barrier), and the density of foam (it is light, but heavier than air–of course), foam can be 4 times more effective than fiberglass. If you have lived in an older, poorly insulated home, you know that heating and cooling bills can really get out of control with a poor insulation. This is just one final cost factor which should be considered when you’re comparing an insulated roof like SPF with other roofing materials, like EPDM, Single Ply, or BUR, with no insulation.