Lay the roofing felt and bitumen welding line yourself
- Safety measures
- Working on the roof
- Working with welding equipment
- roofing felt
- Install roofing felt correctly
- Important instructions for laying
- Bitumen sheeting
- Basic selection
- gas burner
- Correct laying of bituminous membranes
- Control and renewal
When it comes to the covering of smaller sheds or garage roofs, the roofer is rarely called. In order to make it really correct and avoid errors without technical guidance, we have provided a detailed DIY guide for you.
Above all, roofs should be one thing: close. To ensure that this is really safe, roofing with roofing felt and / or with bituminous welding membranes must first and foremost be done professionally. There are many things to keep in mind and procedures that have been proven in roofing practice.
For smaller roofs, you can do the covering yourself, if you have some skill, and works carefully. On larger or complicated roofs (dormers, complicated roof courses, difficult seals) one should leave only the roofer. Here you can get without expertise usually not a hundred percent tight and permanent coverage.
Roofing felt and bituminous membranes are among the classics when covering smaller roofs for sheds and garden sheds, but also especially when sealing flat roofs. (Sloping roofs are covered, flat roofs, however, sealed).
They are still preferred by roofing companies today, alternatives such as EPDM films have not been able to prevail, even if they promise a permanent and irreplaceable roof waterproofing. In practice today is still covered or sealed with roofing felt and bituminous membranes.
For simple sealing a double layer of roofing felt is sufficient. If roofing felt is used as a top layer, the roof seal is quite resistant and lasts several years. The use of welding equipment is eliminated, the application of roofing felt is relatively easy even for inexperienced.
On the other hand, bituminous membranes ensure a better and more effective sealing of the roof, but are also more difficult to apply. Although a cover layer with roofing felt and a welded bituminous membrane above it is not really quite up-to-date in professional circles, it is still often done in practice. This type of combined sealing has also proven its worth over decades.
Every covering and waterproofing with roofing membranes or bitumen membranes should be checked annually and renewed if necessary.
Working on the roof
All work on the roof is subject to basic safety precautions, which should definitely be observed:
- Only those who are free from giddiness, rested and completely healthy may travel to the roof
- all work on the roof is obliged to protect against crashes as much as possible (no matter how high the roof is)
- around the roof surface no objects are to be stored, at which one could incur serious injuries in case of a crash (tool boxes, or the like) it is often not thought
- when working on roofs, firm and non-slip footwear must always be worn
Working with welding equipment
If you work with bituminous membranes, and thus also with welding equipment on the roof, there are a few more indispensable safety measures:
- It is essential to wear long-sleeved clothing and very sturdy footwear (bitumen splashes can cause severe and very painful injuries), and the clothing should not be flammable if possible
- When handling the welding machine it is essential to follow the operating instructions and to exercise extreme caution
- it is essential to wear suitable gloves (heat-resistant and made of leather)
- On the roof always suitable extinguishing agents must be available
- Working with bituminous membranes should always be done with a helper and not alone
These security measures are fundamental and no alternative. Any non-compliance can lead to problems after an accident and be interpreted as negligence.
Roofing boards are today particularly resistant, durable and environmentally friendly. The previously used "tar paper", which did not contain bitumen but carcinogenic tar, is no longer available today.
Roofing felt is generally not completely waterproof (as opposed to bituminous welding), but can often provide adequate weather protection, depending on the nature of the underlying roof skin.
Roofing boards can
- be sprinkled with gravel
This brings differences in UV resistance with it. Coated roofing pylons are only at the top in multi-layer nailing, while uncoated roofing boards are used underneath. Advice on the suitable roofing felt is available from specialized dealers. As a rule, roofing felt R333 is nowhere near sufficient, but in any case the use of roofing felt V13 or higher is recommended.
Install roofing felt correctly
Step 1: Identify needs and prepare roof
The roof must be free of protruding parts and pointed materials that could damage the roofing felt. It is best to sweep the roof swept clean before. Damp areas or damage to substructure elements must first be repaired.
The need can be determined simply based on the square footage of the roof area. But you have to take into account the overlap of about 10 cm per lane. Since roof paper rolls usually measure 1 mx 10 m, the demand calculation is quite simple.
Step 2: Lay the first train
Cut the web and secure it to the edge of the roof with approx. 2 cm of overlap with roofing paper nails. It always starts at the lower end of the roof. The webs can be fixed in the first layer only temporarily, and only when all tracks are laid, finally nailed.
Step 3: Lay other tracks
Cut the web to the required length and place it with 10 cm offset over the previous web. At the top, fold over the supernatant and cut with a sharp knife to a length of 10 cm.
Step 4: Laying the second layer
A second layer can now be laid as well as the first layer (but with offset). Alternatively, it is also possible to extend an asphaltic welding track for this second layer.
Important instructions for laying
Self-adhesive roofing felt can make work easier, but usually also causes much more frequent repair work later. Most optimal is the nailing with special roofing nails. The roofing nails must always be flush with the roofing felt, so that no water can penetrate underneath. Ensure sufficient attachment with enough nails.
Bonding the roofing felt to the bumps is difficult and requires skill. From gluing the overlap points you should rather look out and instead use a bitumen welding line as a second layer.
Bitumen welding sheets, when heated, remove bitumen, which then cools again and forms a watertight, durable bond.
The types and designs in the trade are extremely diverse, but you can almost always disregard certain special bitumen welds when choosing:
- Bituminous membranes with copper inlays serve only as protection against rooting in green roofs, since roots with this inlay can not penetrate the bituminous membrane
- As a rule, bituminous sealing strips with an aluminum insert are only used if the bitumen roofing membrane is to act as a vapor barrier at the same time
- So-called high-quality railways, with particularly high-quality properties are usually superfluous for simple roof waterproofing
Normally, PB webs (polymer bitumen, addition of plastics to the bitumen) are used. Elastomer sheets (EB) are more sensitive and have a lower heat resistance, which is why they usually require an additional radiation protection in technical practice. Also, the laying of these elastic webs is extremely difficult and barely gain as a layman.
PB (or PYB) passes are therefore the most suitable choice for self-service. For use on smaller roofs, the often quite cheap V 60 S4 runway in supplied variant as a top layer is almost always sufficiently suitable. Talc variants are slightly more sensitive, take footprints and are problematic when heated too high. Better to use the sham variant.
In order for a bituminous welding track to be tightly glued, its underside must be heated with a special gas burner. In general, a simple Aufschweißbrenner enough with about 15 - 20 kW power, standard burners, however, have already about twice to four times the power.
The purchase of these devices is extremely expensive, but you can borrow them in many hardware stores for the work also. However, one must always make sure that the equipment is in perfect condition, and all connections are completely sealed. In addition, you should get a basic instruction in handling the burner.
Dangers when using the gas burner
All gas burners for the heating of bituminous membranes are very efficient, therefore, extreme caution is required when handling. Too high a temperature can quickly cause a smoldering fire of the substructure and thus a destruction of the entire building. For this reason, sufficiently suitable extinguishing agents must be available on the roof
IMPORTANT: Do not attempt extinguishing with water with heated bitumen!
Correct laying of bituminous membranes
Step 1: Make the lower layer
The laying of a roofing felt layer as a base for the weld seam sealing in roofing circles is no longer completely compliant, but is often still used in practice and is certainly a recommendable variant for the DiY area, which has proven itself well for a long time.
So make a single-layer roofing felt layer as a base. How to do this, you can see in the instructions above.
Step 2: Rolling out and aligning the bituminous welding track
At first, the bitumen welding roller has to be installed on the roof, together with the burner, the gas cylinder and the extinguishing agents. For this you will usually need a helper, because already 5 meters of bitumen welding tracks are so heavy that you probably will not get them alone on the roof.
The track is first rolled out about 2 meters, and perfectly aligned. You start, as with the roofing felt, here too at the bottom of the roof. Note that after sticking the web can not be corrected - a perfect alignment is therefore essential.
Step 3: Sticking the first web
The aligned web is now carefully rolled up again (to about half meter or meter). Then carefully (!) The lower layer of the web is heated with the burner until the bitumen becomes liquid and reaches a viscous consistency.
The right temperature is crucial here: too little heated webs do not stick tightly, too high heating (bitumen is very liquid) can lead to the destruction of the web, and in addition, even smoldering fires can occur if improperly heated.
The heated underside is now rolled slowly with the foot and carefully (!) Stuck. You must be careful not to damage the surface of the web as possible. It is always only a small piece of heated and solid, so that the bituminous wraparound everywhere safely and sufficiently sticks.
Be careful not to change the orientation of the web as you will not be able to correct it later.
Step 4: Gluing the other webs
The other tracks are also applied in the same way. Make sure that the overlapping of the welding tracks is always at least 10 - 15 cm (better a little more). Work carefully and slowly, paying special attention to the correct alignment of the individual webs. This is fundamental if you want to achieve a clean and effective seal.
Step 5: Making a roof finish
If all bituminous membranes are laid, you still have to make a roof seal at the roof edges. As a rule, one uses canted plates, which are attached to the roof edges. Roofers often have their own curb, where they can easily produce the required sheets themselves. But you can also buy folded sheets and cut or cut them.
Alternatively, the screwing of matching roof strips is a possibility, but not so good. But in practice it is often sufficient.
The roof closure must also be sealed properly. You can use different sealants . Also Bitumendickbeschichtungen are possible, besides there are also other sealants in the trade.
Hot bitumen sealing is more for professionals, and requires experience and skill. As a rule, you can also manage with simple sealing methods.
Step 6: Additional seals
In the professional sector, the bituminous welding track is often additionally sealed at the seams (overlapping points) in order to prevent ingress of water. In addition, various coatings and impregnations can also increase the durability and waterproofness of the bitumen weld sheet.
In practice, all that is rarely necessary. Regular inspections and occasional repair work are required anyway for roofs sealed with welding tracks and can not be avoided by coatings.
However, what you have to look out for is a correct and effective sealing of all connections on the roof and all roof penetrations. Also, the rainwater runoff for flat roofs must be sufficiently sealed, which can be quite tricky, depending on the type of execution, to get a really clean and effective seal. It's best to seek the advice of a roofer on how to best seal the rainwater runoff in your case. In practice, insufficient sealing in this area is one of the most common causes of water damage to the roof - so be careful here.
Control and renewal
No roof seal lasts forever. You should therefore inspect your roof at least once a year for damage, in case of detected leaks you should act immediately. Small damage can be repaired with bituminous thick coatings, however, in the case of major or unclear damages (no direct damage visible) a complete renewal of the roof covering or waterproofing is advisable.
New coatings can be applied to old coatings a few times, but then the entire seal must be removed and re-applied (risk of fire due to spontaneous combustion). In case of doubt always ask your roofer for advice on all roof work - his experienced eye and his experience will help you to avoid damage.
Tips for quick readers:
- always use suitable roofing membranes and bituminous membranes
- It is essential to comply with the required safety measures
- The best way to nail roofing felt
- Ensure sufficient overlap of the webs
- Ensure proper handling of the gas burner
- To help the helper
- Pay attention to correct orientation of the bituminous welding track
- Check roofs regularly
- Repair damage immediately or replace cover (seal)