In some areas, gravel covered home roofs are common. Customers also requested information to help direct them through reflective coatings to turn these roofs to “cool roofs.” Not all gravel roofs and spray foam roofing are suitable for conversion, so please read this bulletin carefully before continuing.
Gravel Roof Pros
Most gravel roofs are inexpensive to build, provide some protection against UV damage to vulnerable asphalt, and the stones are very durable.
White Coating Advantages
Spray foam roofing coat the white roof lowers rooftop temperatures and, by lower temperatures and protective coating, prolongs roof life.
Cooling costs will reduce and it is much simpler to service the roof.
The total weight on the roof is decreased, and it is possible to repeatedly renew the roof protection.
What you have to avoid
- Do not directly apply coating over gravel; this is expensive and guaranteed to fail.
- Do not add a cloth membrane to a gravel roof; unless the surface has been filled and smoothed, this is expensive and guaranteed to fail.
- Do not add a covering to a roof that is badly worn or dried out.
- Stop applying coating to roofs that need repair (fix these first).
- Stop adding coatings to roofs with severe problems with standing water.
The Steps
1. Determine if the roof is a successful coating candidate. It is costly and frustrating to try to save a poor roof.
Is the roof less than 10 years old? In order to survive, older roofs may be too frail.
Is the folding layer flexible? Find the ply sheet edges at the seams and around penetrations; to assess versatility, bend side to side. Roofers may elect to take a sample of the heart. Do not cover roofs with inflexible, dried-out ply content.
Consider the state of the roof, ventilation, cooler or AC leaks, and any required repairs. Stop the issue of coating roofs.
2. Decide in advance on how to dispose of the removed gravel.
Can it be scattered around the property or must it be taken away?
What’s going to cost disposal?
Where will gravel be taken off the roof and what arrangements for the ground (i.e. tarp, containers, truck bed) need to be made?
3. Remove all the loose gravel carefully without damaging the roof membrane.
For extracting free gravel, use a push broom and coal shovel.
Asphalt and gravel clots are popular. Without damaging the roof layer, remove as much as possible. Later on, clots may be coated over.
Any pits and clots that are visible will still have gravel roofs.
4. Wash the roof membrane with pressure and fix any issues.
Check and fix all lap seams as needed. Use Elastek Crack & Joint Sealant and fabric to strengthen as required.
Caulk both crack and joint sealant roof penetrations with. Use fabric to strengthen as needed. A proficient roofing company will never skip this step.
Replace the gravel-stop and drip edge with traditional material or flatten the raised lip gently enough to facilitate good drainage.
5. Apply two thick asphalt emulsion coats and allow for healing for a week or more.
Emulsion is an economical way to fill in the many stone pits on the surface of the roof when resealing the membrane as well. It is less costly to use than a white elastomeric layer.
A consistency emulsion such as Elastek Sealer Emulsion is used.
Submit instructions from the emulsion manufacturer. In warm weather, this is best achieved.
6. Apply at least two layers of suitable Elastek coating.
For longevity and long life, use either Elastek Solar MasticTM or Solar Tek ExtremeTM.
As a first coat where drainage is marginal, use Solar Tek ExtremeTM.
Coat all asphalt surfaces, parapet flashing above the roof or counter flashing addition, and penetration above the sealant line.
Periodic Coating Renewal
See us at Preferred Roofing for roofing coat. For residential or commercial roofing projects reach us at Preferred Roofing. Being truly yours roofing company we are always at your service.