There have been and will continue to be coating manufacturers that make claims to provide a complete, long-lasting waterproofing system. We have seen many coating systems fail over the years. The failures seem to occur because the material directly under the coating moved, the chemical composition of the coating peeled or, moisture or air came from underneath the coating or was encapsulated when the coating was applied. We used to believe that coatings were not good for waterproofing but only for reflecting sunlight. We believe that coatings can be proper water-proofing layers if the surface is prepared properly and the coating applied correctly. Coating manufacturers claim to be useable on all types of roofing. We believe the most appropriate place for a coating is on a metal roof. To do this correctly usually has to meet a host of conditions:
- The temperature range usually has to be over 40 degrees Farenheit and less than some temperature (depends on coating).
- The fasteners have to be treated first with mesh or extra caulking.
- The seams have to be treated with mesh.
- Excess rust has to be treated.
We have priced out applying coatings to EPDM roofs – the coating manufacturer required a foundation coat, mesh over the entire roof in that coat, another foundation coat then 2 finished coatings. This ended up costing much more than adding a new layer of insulation and an EPDM membrane. Coating a modified bitumem or built-up roof may also yield a few extra years of leak relief.