The Roofing Resource Blog

Metal Roof Repair - PVC Metal Roof Recover FAQ

Tue, Apr 5, 2016 @ 09:00 AM | Perry

1. How can you screw down the PVC membrane without poking holes in it that leak?

The membrane is screwed down every five feet using screws and plates. The plates act like a washer helping to hold the membrane over a larger surface area. The screws and plates are usually placed 12” on center. The next sheet of PVC is then layered over top of the line of fasteners and usually over laps the line of screws and plates by 6”.  Then, the two sheets are hot air welded together which forms a permeant water tight seam The over lap covers the screws and this is how you can screw down a membrane without poking holes in it that leak. 

2. How long is this PVC metal roof recovery system guarantied for ?

There is a 15 year and a 20 year system. The difference is the thickness in PVC material, all the trims, flashings, and application techniques are the same. 

3. Is the warranty included in the price ?

Yes, the 15 year warranty comes standard and the optional 20 year warranty cost and aproximatley .25 cent per sq ft. This includes moving up in thickness of membrane and extending the warranty.  

4. How much does a PVC metal roof recover cost? 

The price will vary depending on the existing metal roof  profile to be covered and the amount of insulation along with the sq. footage and amount of stacks and flashing on the roof but an  average price of $3.00 per sq. Ft installed will get you close. Larger jobs may be less and smaller jobs may be more. 

5. How long does it take to install?

The metal roof lay over is a very fast installation, we can usually installed anywhere between 7,000 and 10,000 sq. Ft per day. 

6. Does the white color of the membrane really help reduce heating? 

Yes, it does, the white membrane reflects heat in the summer and can reduce heating and cooling cost by up to 15% and for uncooled buildings it creates a more tolerable working temperature for employees and staff working inside the building.


7. How does this compare to a metal roof coating?

This is different from a coating in that the membrane is manufactured in a controlled environment and is only installed on the job site whereas a metal roof coating is basically building a membrane on top of the metal roof one layer at a time. Most coatings consist of a good power wash or chemical wash to remove dirt, a base layer that must have a mesh rolled into it while it is wet and then two top coats. Each time  a layer is installed the weather must cooperated and the the coating must dry completely before applying the next coat. We find this to be very difficult with morning and evening dew on the metal and high humidity and pop up thunderstorms during summer months. The PVC membrane allows us to work in a variety of weather conditions and since we are not removing the existing roof we are not exposing the building to rain or snow and we dont have to worry about dry times like we do with metal roof coatings. 

8. How does it compare cost wise to a metal roof coating?

If the metal roof coating is a warrantied project with multiple coats of paint the PVC metal roof recover is usually much less expensive. If a coater is only going to slop tar or spray one thin layer without prepping the surface correctly the coating will be cheaper. Basically the only way a metal roof coating can beat a PVC metal roof recover is to cut corners on the products and installation. 

9. What about along the walls of my building, this is where we have many leaks?

This is one area that the PVC metal roof recover really works great as we are able to use the membrane to go up and over the walls encapsulating the entire wall. Metal roof coatings often fail along this transition because of thermal movement. The movement of the masonry wall and of the metal roof is very different and the coatings can’t flex enough to hold a seal on both substrates. 

10. What happens in 20 years? 

Simple, you remove the old PVC membrane but leave the insulation and filler in place and install a new PVC membrane. 

11. How much does it weigh? 

The PVC membrane only weighs about 1/4 pound per square Foot

12. Is it easy to repair?

The PVC is very easy to repair, simply clean the area to be repaired with acetone sold at your local paint store and hot air weld a patch on. The great thing about the PVC is that is will hold a weld throughout its entire life cycle so it can easily be repair even as it ages, this is not the case with other membranes especially TPO as it looses it ability to hold a hot air weld and therefore is difficult to repair as it ages  

13. Are the seams Glued together?

The seams are hot air welded and do not rely on glue or caulking to stay water tight. Watch our video on hot air welding to learn more 

14. How are the flashings down? 

The PVC membrane is more than just rubber roofing, its a complete roofing system that has custom sized flashing to fit even the trickest metal roofing detail . The Flashings around HVAC units and Stacks are all custom sized to fit then hot air welded down. The PVC recover system’s accessories include inside and outside corners, custom sized  stack flashings, custom sized HVAC flashings, edge metal, pitch pockets for line sets, custom through the wall scuppers and collector head boxes for drainage.

15. Do I have to change my gutters?

No, you can leave the existing gutters in place and terminate the PVC membrane into them or use a metal drip edge at the existing gutter. 


Topics: Commercial Roof, Metal Roof Recover