Durable, continuous waterproofing from an aged asphalt shingle roof
Bitumen asphalt shingle was a popular roofing material for many years, as it offered an attractive appearance and a wide range of design options. Over time, however, more and more asphalt shingle roofs show typical signs of ageing: the shingle sheets delaminate, crack, lose their flexibility, fixings loosen, and leaks can develop at joints.
Areas around valleys, eaves, roof windows, chimneys and other roof penetrations can be particularly sensitive. Failure of the covering made up of smaller, individual shingle elements is often not limited to a single point, which is why patch repairs often only provide a temporary solution.
With the refurbishment technology we use, an asphalt shingle covering in suitable condition can in many cases be refurbished without full stripping. Above the existing roof we create a continuous, modified bitumen waterproofing layer that provides uniform protection across the entire roof surface instead of the shingle’s individual elements.
Omitting stripping can significantly reduce the duration, cost and amount of waste generated by the works. The condition is that the existing roof structure and substrate are technically suitable for refurbishment – this is verified in every case by an on-site condition survey.
The asphalt shingle roof refurbishment process
Survey of the roof condition
First we examine the condition of the shingle covering, the substrate structure, the eaves, the valleys, the roof penetrations and the flashing structures. We identify the possible causes of leaks and determine whether the roof is suitable for refurbishment without stripping.
No two roofs are the same, which is why we do not think in template solutions: the required layer build-up and detailing are always tailored to the specific building.
Cleaning and surface repairs
We thoroughly clean the roof surface of dust, contaminants, moss and adhesion-inhibiting substances. We repair delaminated or damaged shingle sections, secure loose elements, and restore substrate sections in unsuitable condition as necessary.
Waterproofing can only be long-term secure on a stable, properly prepared substrate.
Formation of the eaves line and flashing connections
We release, inspect and, where necessary, repair or supplement the flashing at the lower edge of the roof. We connect the waterproofing to this properly secured metal sheet, thereby creating reliable and durable water drainage at the eaves line as well.
Bitumen priming
We treat the properly prepared surface with a bitumen primer. The primer binds the remaining dust, equalises the surface’s moisture absorption capacity, and promotes proper adhesion between the old shingle and the new waterproofing membrane.
Formation of roof ventilation
During asphalt shingle roof refurbishment, preserving the hygrothermal functioning of the roof structure is particularly important. We check the existing ventilation, and where the roof design warrants it, we install new vapour vents or supplementary ventilation elements.
This reduces the risk of moisture trapped in the roof structure causing damage later.
Reinforcement of roof details
We prepare the surroundings of valleys, chimneys, roof windows, vents, penetrations and other connections with particular care. In heavily stressed areas we apply additional waterproofing layers and reinforcements.
A roof’s reliability is determined not only by the large surfaces, but above all by the properly designed details.
The installation of modified bitumen waterproofing
We install a polyester-fleece carrier-layer modified bitumen waterproofing membrane onto the prepared surface. The membranes are cut to match the roof geometry, then fixed with torch-on adhesive, and the overlaps are welded across their full area.
The mineral granule surfacing on the top side protects the waterproofing from UV radiation and weathering. The finished layer provides the roof with a continuous, high tensile-strength and flexible protection.
Inspection and handover
At the end of the works we inspect the overlaps, junctions, flashings and all roof penetrations. After cleaning the work area, we hand over the roof in a technically inspected condition.
Why is it worth refurbishing the asphalt shingle roof in time?
- A covering in suitable condition can in many cases be refurbished without full stripping.
- The significant extra cost and waste generation associated with stripping can be avoided.
- A continuous waterproofing layer is created above the individual asphalt shingles.
- We reinforce the roof’s most sensitive junctions and penetrations.
- The roof’s appearance will be aesthetic and uniform.
- We provide a written workmanship warranty of up to 10 years for a refurbishment carried out with the proper technical content.
If your asphalt shingle roof has aged, delaminated, or the first signs of leakage have appeared, it is worth intervening before the substrate structure suffers more serious damage.
Request an on-site survey and a detailed, itemised quote!
Problem with your roof?
After a free on-site survey we give you an itemised quote.