Laying the bitumen membrane yourself: DIY instructions for roofing felt

Putting a bitumen sheeting on the roof of a carport, gazebo or tool shed is basically very simple. The roofing felt is cut to size and fastened with suitable materials. However, for a high level of impermeability and long durability of the top layer, a few points must be taken into account. These depend, among other things, on the type of roof and the speed at which the water drains off.

Types of bitumen sheeting

Roofing felt is available in different designs. The variants are differentiated according to the type of attachment. These are:

• self-adhesive bitumen sheeting
• Bitumen sheeting for attachment with cold glue
• Bitumen sheeting for fastening with hot glue or hot bitumen

An alternative is to fix the roofing felt sheets with roofing felt pins. Simple and very inexpensive bitumen sheets can be used for this. However, they are not always suitable.

Types of fastening - advantages, disadvantages, recommendations

The differences in the type of attachment are not only decisive for the effort involved. The tightness also depends on it. Therefore, when choosing, several factors should be taken into account:
Roofing felt sticks
The simplest and most cost-effective fastening variant is nailing down with roofing felt pins. The roofing felt sheet is placed on the roof, aligned and cut to fit. Then it is pinned down at regular intervals. The procedure can be carried out without any problems even for laypeople without experience. However, it is only suitable for steep roofs from which rainwater runs off quickly. The tightness would not be sufficient on flat roofs. This type of fastening is therefore suitable for steep roofs.

self-adhesive bitumen sheeting
No glue is required for self-adhesive bitumen sheeting. This makes it very easy to attach and is ideal for laypeople and anyone who has no experience in laying and fastening bitumen sheeting. The tightness is also high, so that the self-adhesive bitumen variant is suitable for flat roofs. The only potential disadvantage is the price, which is higher compared to other variants. However, the effort involved in attaching it is also very low.
Bitumen sheeting for attachment with cold glue
The application with cold glue is suitable for laypeople. However, the effort is greater than with the self-adhesive bitumen sheeting. On the other hand, the tightness of the roof is better than when it is fastened with roofing felt pins. Again, this variant is ideal for flatter roofs and for do-it-yourselfers who are laying roofing felt for the first time. The costs are comparatively low. However, the necessary steps must be taken into account.
Bitumen sheeting for fastening with hot glue or hot bitumen
If hot bitumen is laid, a gas burner must be used to fix the individual sheets. The roof is sealed well, but the effort involved is relatively high. In addition, the risk of injuries increases as a gas burner has to be handled.
Laypeople should therefore not try this type of fastening. For this reason, the application of hot bitumen is not further described here.

Preparation - step by step instructions

Regardless of which type of attachment is chosen, some preparatory work steps are always the same. These include:
1. Clean, dry, grease-free
Before the bitumen sheeting is laid, the roof must be cleaned accordingly. With dry and comparatively clean roofs, it is sufficient to sweep the subsurface thoroughly. If there are grease stains, they should be removed at least when attaching with adhesive or self-adhesive roofing felt. In any case, however, the roof must be dry. Laying should therefore only be carried out in appropriate weather.
Experience has shown that it also makes sense if tarpaulins are available to cover and protect against sudden rainfalls. In this way, it can be avoided that the surprising downpour while the installation is in progress, delaying the work by several days.
2. Plan and cut
The bitumen sheeting should overlap each other by at least five centimeters on the longitudinal edges. This will ensure that the water can drain easily from them. There should also be a protrusion at the outer edges. It is ideal if the individual tracks are offset.
Precise measurements should therefore be taken for planning and cutting and the laying should be sketched out. We recommend using strong, sharp scissors or a cutter knife with a hooked blade for cutting. In both cases, cut-resistant gloves should be worn to avoid injury.
3. primer
If self-adhesive bitumen sheets or bitumen sheets with cold glue are to be laid, a primer must be applied to the roof in preparation. This ensures that the glue then holds really well.

Instructions for attaching with roofing felt pins

Attaching with roofing felt pins is very easy. The following steps are unfortunately necessary:

1. Clean the roof and dry it if necessary

permit.

2. Cut bitumen sheeting to size. Pay attention to the necessary overlap between the individual strips and pieces.

3. Laying begins at the bottom of the roof. The first sheet is aligned with the lower edge of the roof and fixed at regular intervals with roofing felt pins. It is ideal if you work in pairs. One can hold the web while the other fixes it.

4. The second strip is laid so that it protrudes about five centimeters over the first strip. This is done until the entire roof is covered.

Self-adhesive bitumen sheeting

Attaching the self-adhesive bitumen sheeting is very easy. Only the following steps are necessary:

1. Clean the roof and let it dry if necessary.

2. If necessary, apply a primer and let it dry as well. The manufacturer's information should be taken into account here in order to ensure optimum tightness.

3. The tracks are cut, aligned and glued on.

Here, too, work is done from the bottom up and attention is paid to the respective protrusions.

Attach with cold glue

The instructions for attaching with cold glue differ only slightly from those of the self-adhesive bitumen sheeting. However, there is one crucial difference. Please note the following steps:

1. Thoroughly clean the roof and ensure that it is dry.

2. Apply primer and allow to dry sufficiently.

3. Measure and cut the bitumen sheeting.

4. Apply the glue to the roof. It makes sense to apply this only so wide that a sheet can be laid in it.

5. Align the cut sheets of roofing felt on the adhesive bed and press it down, then weight down the bitumen sheets.

6. The overlapping sections must also be puttied and smeared from the outside with the cold adhesive in order to really seal the roof. This is especially important if the roof is rather flat and the water does not run off too quickly.

Whichever type of fastening you choose, the tightness should always be checked afterwards. If edges are not properly taped off or fixed with roofing felt pins, rainwater can also be forced into the roof by strong winds, for example.