The best flat roof roofing material is without a doubt a single sheet of rubber tailor made for weather-proofing flat roofs, such as Firestone’s EPDM product.
This is laid directly onto roof boarding, itself supported by the roof rafters and nagging. Insulating material is generally laid in the space between the two, and if you’re renewing your flat roof anyway you might as well take the chance of renewing that simultaneously.
This will almost certainly function as recommendation you receive from any reputable builder or roofer advising you on replacing your existing flat roof.
Until recently the most used material for a new flat roof was bituminous felt laid in three layers, the initial layer nailed down and top of the two bonded to the main one beneath with mastic bitumen. According to the material used, this may mean heating a solid bitumen-based compound to create it liquid, and then pouring it onto the underlying felt and spreading it evenly over the whole section of the roof.
Then you had to hold back for the compound to cool before applying another layer, and at the end spreading a layer of stone chippings on the roof and bonding it with a chipping compound, this being to reflect natural sunlight and stop the felt and bitumen degrading quickly.
This was altogether a fairly messy, complicated and time-consuming job best left to the professionals. In addition, there have been several stages where it had been very easy to neglect to make the roof weather-proof, e.g. where in fact the edge of the felt met the existing tile or slate roofing of the pitch roof.
On top of that, if, or rather when, there developed a leak in the flat roof, it could be very difficult and messy to find out exactly where the rain was getting back in. Seldom would the manifestation of the leak on the ceiling of the room below be directly below the source of it. Water could easily get through a weakness in the bitumen felt and travel along a rafter before descending to the ceiling board below.
The brand new generation of rubber-based flat roofing systems are far superior. Assuming you have reasonable DIY abilities then you can probably do-it-yourself, with one other person to assist. You can easily find a local supplier of rubber flat roof roofing material online, and the current price is around �6.65 per square metre.
Most suppliers cut the material to the exact size and shape that you require so there are no unnecessary joins, meaning no weaknesses and an extremely long-lasting, leak-proof roof.
The vital area of the whole process is to ensure that there are no gaps between your rubber roof and any existing pitch roof where rain could possibly penetrate. To ensure there are no problems it’s important to run the rubber material up and under the tiles or slates of the adjoining pitch roof so that any rain dripping from the lower-most row falls onto the rubber, with no possibility of it over-lapping the edge and getting underneath the pitch roof.
Also, make sure that the prevailing slope of the flat roof towards the guttering or other method of water escape is maintained. The rubber is merely glued onto the roof boards and sealed where appropriate with metal brackets or bitumen so that rain penetration is impossible. Mind that the glue covers the entire underneath of the rubber to be able to avoid bumps in the top which could obstruct the drainage of the water away.
Professional roofing services have been shown to last for more than 50 years under all weathers, so that it really is the only real flat roof roofing material you need to consider when deciding on a fresh flat roof.