Most warehouses have a low slope roof. This means that the roof is either flat, or has such a low pitch as to be nearly flat. Low slope roofs can't really be made of the same kind of roofing material that a high slope roof can be. That's because the water doesn't run off the roof in the same way. The roofer is going to have to use different kinds of material and different techniques in order to make sure your warehouse roof is going to last for a long time. One option is to use a built-up roof system.
Built-up roofs consist of layers of membranes or other roofing materials that are laid down on the roof. In between each of those layers a layer of bitumen is applied. Bitumen is a sticky substance that comes from the production of petroleum products. It generally needs to be applied hot so that it is in a more liquid state.
The bottom layer of one of these roofs can be applied using mechanical means, such as nails or screws, however it's more common that the layer is put on the roof with the bitumen. Once the bitumen has been applied, it's time to add another layer of roofing material. Generally that material is a kind of roofing felt.
Many of these roofs are 4-ply roofs, meaning that there are 3 layers of roofing felt plus the bottom layer, interspersed with the bitumen. Bitumen is also applied over the top layer of material. This is done to help seal the roof so that it's water resistant. It also helps keep the top layer secured to the rest of the roof.
After the top layer of bitumen sets, the roof can be finished. There are a few ways that it can be finished. One option is to use gravel that is scattered over the bitumen before it completely dries and sets. Another option is to use paint. The bitumen roofing material holds the paint well. If the roof is painted white, it can help reflect heat away from the roof, which can help keep the building under it cooler, helping to keep the utility bills down.
Making sure that a warehouse gets the right kind of roofing installed is important. Otherwise, the roof could leak or even collapse. A built-up roof can help with those problems and help make sure water doesn't run the roof or anything under it. Contact a commercial roofing contractor for more information.