If you're getting a new membrane roof on your commercial building, you and the roofer have a lot to plan out. You'll want the process to be as easy on your employees and customers as possible. Plus, you probably want to get the process over as quickly as possible. However, the roofer can't cut corners when it comes to proper technique because you want your new roof to last as long as possible. Here are two flat roofing installation decisions you'll need to make. 

1. What Goes Under The New Membrane

Membrane roofing is pretty thin, so it's usually put over something. That's why a new membrane is often put over an old roof. Before this can be done, the roofer has to take a moisture survey of the old roof to see how much water damage it has. If there is too much water damage, the old roofing has to come off and the new roof started at the deck. If there isn't a lot of water damage, the new membrane can be applied over the old roof.

A membrane isn't usually placed right on the deck if the old roof has to come off. The deck of your commercial building could be metal, or it might be wood. Neither one of those materials will insulate the building. Plus, if either gets wet due to a membrane leak, the deck could be damaged by rot or corrosion.

To prevent this, the roofer will put down cover boards or insulation boards. The boards add insulation and they also provide water protection by keeping water away from the deck for as long as possible. These have varying thicknesses so the roofer can use them to create a slight slope for drainage toward a roof drain too.

2. How The Membrane Roofing Is Attached

Another important consideration with flat roofing installation is how the membrane will be attached. You might prefer gluing the membrane to the roof. A fully adhered membrane is uniformly secured to the roof so no part of it is loose to flap around.

Another option is to use fasteners. These are used along the edges on each side of the membrane. There are a couple of disadvantages with this method. One is that the fasteners make holes in the boards under the membrane and another is that there is nothing holding down the inner part of the membrane. This creates the potential for air to get under the membrane and make it puff up.

A third way to attach membrane roofing is to hold it down with rocks. This works if your roof can support the weight of the rocks. The rocks keep the membrane held in place and they also protect the membrane from damage and sun exposure.

Your commercial roofing contractor can help you choose the right flat roofing installation method for your building so your roof stays securely in place and lasts a long time.

Contact a local roofing service, such as Diamond Roofers LLP, to learn more.