Flat Roof Replacement Cost for Commercial or Residential Buildings

More often than not, the first question a customer asks is: what is my flat roof replacement cost going to be?

Obviously, commercial flat roofs and low-slope roofs on residential properties vary from project to project. As you can imagine, there are so many roofing system options now available in the marketplace it is hard to give an exact price for a flat roof.

We can break down some of the systems that you can have installed on flat roofs and low sloped roofs as follows.

Please note the pricing guide below does not factor in any insulation boards, flat or sloped insulation. Please do not hesitate to contact us and we can talk you through which would be the best option for your project.

These prices would also vary depending on how many roof drains/scuppers, A/C units and penetrations there are on the roof system you choose.

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EPS AND ISO INSULATION BOARDS

We also have flat roof systems with EPS and ISO insulation boards installed under the roof systems.

EPS insulation boards are commonly used for sloping a roof system to the drain and scupper areas; this is a more economical way and is available with slopes of 1%, 2%,3%, 4%, or even high.

ISO insulation boards are designed to offer improved thermal resistance; a better R-value. ISO is a Polyisocyanurate insulation panel available in 4 ft × 4 ft or 4 ft × 8 ft and can vary in thickness depending upon what R-value your project is looking to gain.

Both EPS and ISO insulation boards can be used in the other flat roofing or low-sloped roofing systems, which are shown below.

HERE ARE SOME FLAT ROOF REPLACEMENT OPTIONS & HOW MUCH THE OTHER DIFFERENT SYSTEMS COST

2-PLY SBS ROOFING SYSTEM COST:

The 2-ply SBS roof system is one of the most popular roofing systems used in today’s new construction and re-roofing projects, consisting of polyester or fiberglass reinforcing mat sandwiched between two layers.

One flat roof system that can be used on flat roofs and low slope roofs is a product called a ProtectoBase board; this comes with a factory-laminated SBS bitumen base sheet membrane fixed to the main roof or on top of insulation boards.

Then a layer of mineral cap sheet is torch-applied on top of the ProtectoBase board, making this a 2-ply flat roofing system. All up-stand/curb details and perimeters of the roof are done with a base sheet and then a mineral cap sheet. For example, you can even have a 180 or 250 mineral cap sheet installed over the ProtectoBase.

The new construction flat roof’s approximate price per sq foot would be between $7.50 to $11.50 Sq Ft

Re-roofing a flat roof approximate price per sq foot would be between $8.5 to $14.00 Sq Ft

Please note:

West Point Roofing has stopped using the FR Board system and have upgraded all of our customers to the ProtectoBase board; the FR Board system has a tendency to delaminate from the roof area, the ARCA will no longer approve or warranty this product in any future roofing projects.

SINGLE-PLY MEMBRANE SYSTEMS COST (TPO/PVC)

TPO (thermoplastic polyolefin) single-ply roof systems are more cost-effective on large flat roof areas. This flat roofing system is more commonly installed with hot air guns and heat welded to fuse the two membranes together.

The new construction flat roof approximate price per sq foot would be between $6.90 to $11.20 Sq Ft.

Re-roofing a flat roof approximate price per sq foot would be between $7.85 to $12.50 Sq Ft

EPDM COST (SINGLE PLY)

EPDM (ethylene propylene diene terpolymer) is also single-ply roofing system, this single-ply membrane comes in various thicknesses and can be installed in different applications, such as a loose layer and then ballasted over with rock or a fully bonded system on top of a ISOGard HD board.

New construction flat roof approximate price per sq foot would be between $4.50 to $8.50 Sq Ft

Re-roofing a flat roof approximate price per sq foot would be between $5.5 to $9.50 Sq Ft

4-PLY ASPHALT AND GRAVEL COST (BUR)

4-ply asphalt and gravel roof system consists of four piles of felt embedded in hot asphalt and then a flood coat for the gravel. These systems are generally installed on very large roofs.

Previously this system was always used on all types of flat and low slope roofs, but with health and safety now stricter and the new flat roofing systems that are available, it does make it more cost effective to use a 2 ply or single ply system compared to this one.

New construction flat roof approximate price per sq foot would be between $7.80 to $12.50 Sq Ft

Re-roofing a flat roof approximate price per sq foot would be between $8.60 to $14.50 Sq Ft

I hope you find the above information a useful guide to assisting you when choosing a flat roofing system which will be of benefit to you and offer long-lasting performance.

Please do not hesitate to contact us and take advantage of our free roof inspection, whereby we can offer a more detailed explanation and guidance on what is suitable for your next flat roofing replacement.