Heat Welding on the Roof: Explained

The most common insurance claims in the roofing industry involve water damage. When roofs don’t get sealed properly, moisture from storms and melted snow can easily slip through. It can then damage not just the roof, but other parts of a building. 

Issues such as these can cost your roofing company time, money, and credibility. Luckily, there's a method you can use to avoid them by making each roof more waterproof. This method is called heat welding. 

If you want to learn more about this method and how it can benefit your company and customers, read on. 

What is Roof Heat Welding? 

When contractors build a commercial roof, they often use polyvinyl chloride (PVC) membrane sheets as the roof’s top layer. PVC is like other plastics, such as thermoplastic olefin (TPO). Manufacturers make it by combining chlorine from rock salt with ethylene from fuel.

Two of the features which make PVC roofing membranes so popular are their durability and water resistance. However, how well these membranes resist water differs between installations. This often has to do with how roofers cover the seals between different PVC membranes.

PVC roofing membranes aren’t usually large enough to cover an entire roof. Roofers instead have to take different-sized sheets and lay them together. This leaves holes or seams between the membrane sheets. 

Roofers will often cover these seams with glue or another material. Heat welding is another method. It involves fusing two PVC sheets together until the seams no longer exist. 

What is the Process of Roof Welding? 

Before even laying down the membrane sheets a roofer must have the right heat welding equipment. Luckily, unlike other welding processes, this one doesn't involve complex machinery like lasers. Rather, all that a roofer needs is a specialized machine known as a heat welder and the necessary accessories. 

Once contractors purchase this, they will bring this machine to the roofing site. After they finish placing the PVC membrane sheets, they will bring the heat welder up onto the roof. Then, one of them will take the heat welder and place it on a seam between sheets.

He or she will turn on the heat welder. Then, the contractor will move it along the seam. Once he or she reaches the other side, the seam between the two membranes should have disappeared. 

How Does This Process Work? 

What did the heat welder do to fuse the two membrane sheets together? Like the other welding processes mentioned above, the heat welder used heat to combine the two materials. However, it didn't have to use such complex tools as lasers to do so. 

Plastics have much lower melting points than metals. Thus, heat welders don't have to produce very high temperatures to melt them. These machines can simply use hot air welding to do this. 

While a heat welder is operating, it blows hot air at the seam between the two membrane sheets. The machine produces this from a tube that lets out next to one or more wheels. If the roofer stands long enough in this position, the edges of the sheets will melt and pool together. 

Next, the roofer will push the wheel or wheels over the melted plastic pool. This forces the plastic molecules together and flattens out the surface. Once the roofer feels satisfied, he or she will leave this section to cool down and move on to the next one. 

The roofer will then repeat these actions for the rest of the seams. 

What Are the Benefits of Hot Air Roof Welding? 

Roofers will not only find that the hot air roof welding process is better than other seam sealing processes, but they will also see their customers gain significant benefits from heat welded roofs. For some examples of these, check out the list below. 

Roof Welding Is a Safe Process 

Other welding techniques often involve dangerous equipment. Welders often have to wear special safety equipment. If not, they face the possibility of becoming blinded or burned. 

The same isn’t true for hot air roof welding. There’s no light, fire, or other dangers involved. The air a heat welder blows can become hot, but it can be avoided easily. 

Heat Welders Can Finish Their Work Quickly 

It takes some time for the plastic to melt. However, heat welders work faster than you may think. Many can weld between seven to fifteen feet per minute. 

In addition, many heat welders have adjustable temperatures and speeds. This can help when you need to complete work faster than usual. 

PVC Membranes Can Be Welded in Cold Weather 

It's not ideal for roofers to attempt hot air welding in cold temperatures. However, it isn't impossible. It may take more time, but a roofing team can still achieve some quality work. 

The same isn’t true with glue. Many adhesives cannot become fully viable in cold weather. Therefore, a roofing company can lose profits when they’re unable to work in cold weather. 

Welded PVC Roofing Takes Less Time to Be Ready

The heated plastic can take some time to cool down. Once it does, it will be at its best strength. The roofers can then start adding other features to the roof, such as a coating, right away.

The same isn’t true for glue. Even in great conditions, it can still take some time to cure and dry. 

Welded Sheets Stay Together

When PVC membrane sheets are heat melded together, they become one large sheet. Even if the wind somehow rips off all the roofing, all the membrane sheets will stay together. The only way a person can separate them again is with a sharp tool, like a knife.

The same isn’t true with glue. A seam seal that roofers create with it only lasts as long as it does. It can still break down and cause the membrane sheets to separate. 

Heat Welded Roofs Are More Waterproof 

Moisture can break down glues and adhesives. On a roof, especially in a rainy and/or snowy climate, a lot of moisture will come into contact with it. Unless the roofers have added an extra coating, the glue will be helpless to the effects of the moisture. 

The breaking down of the glue won't only cause the membrane sheets to break loose. It will also allow for moisture to slip in through the seams. It can then leak into the building below and/or cause damage to other parts of the roof. 

Heat welded membranes will not have that issue. The seams between sheets are no longer in existence. There's also nothing for the moisture to break down. 

Heat Welded Roofing Is More Windproof 

Glue-sealed seams can also face trouble with high winds. It likely won’t be an issue when the membrane sheets are first set down and adhered to each other. The fact that the sheets have remained individual makes them weaker, but not too weak. 

Most problems can occur after the moisture loosens the glue. High winds can get under the individual membrane sheets. They can then rip the sheets off and leave your roof vulnerable. 

The wind can’t get under the non-existent seams of heat welded PVC roofing membranes. Thus, it’s less likely that the wind will rip them off. 

Choose Us to Be Your Heat Welder Supplier

In summary, roof heat welding is an easy, safe, and effective process that will leave your customers satisfied. As a result, your business will gain more profit from an increased reputation and a busier, more efficient working schedule. 

If you’re ready to purchase a heat welder, look at our offers first. With over 70 years of supplying roofers, we can guarantee that we’ll know just what you and your team need. We also offer fast shipping, so it’s certain that you’ll start your project on time. 

If this sounds interesting, click here to request a free catalog.