Frequently Asked Questions
Everything people ask before committing to a roof.
Recoat or Replace
How do I know if my roof can be coated instead of replaced?
Walk the whole deck. Any soft, spongy, or dished area means wet or rotted decking underneath, and that is a replacement. Then meter the interior ceiling panels against a known-dry area. If the deck is firm everywhere and the meter reads dry, you are a recoat candidate. Widespread membrane delamination or a tear over wet decking sends you to replacement regardless.
My roof has bubbles and lifted areas. Is that disqualifying?
Not necessarily. Small lifted areas mean the adhesive released locally — those can be cut, re-bonded to the deck, and coated over. Widespread lifting across large portions of the roof means the sheet is done and should come off. The test is whether the deck underneath is sound and dry, not whether the sheet is stuck.
Is a coating a shortcut compared to a real replacement?
It is a different assembly, not a lesser one. A replacement gives you a new 45-mil single-ply sheet with the same termination bar, the same cut-and-caulk penetrations, and the same three-to-five year sealant maintenance. A fully bonded 40–60 mil polyurea membrane has none of those. On a sound deck it is the better roof, not the cheaper compromise.
How long does a recoat take?
One to two days depending on unit size and how much old sealant has to be removed. Prep is the long part; spray time on a towable roof is under an hour. The membrane is tack-free within a minute and the unit can go back outside the same afternoon.
Membrane-Specific Questions
Can you really coat over EPDM given how much it chalks?
Yes, and the chalk is exactly why the prep is what it is. Two passes with Super Orange Cleaner and a rinse between removes the migrated plasticizer, and the water-sheet test verifies it — if water beads anywhere, that area is not clean yet. Then 7001 Primer bonds to the rubber and blocks any further plasticizer migration into the new membrane. Skip either step and the coating fails; do both and it holds.
Do I really need primer on TPO? It looks perfectly clean.
Clean TPO is the problem. Thermoplastic polyolefin has an intentionally low surface energy — it is engineered to be non-stick so it stays white. There is nothing for a coating to bond to chemically or mechanically without a primer that bridges it. This is the one substrate where we will not spec the system without 7001.
My fiberglass roof has no seams. Why would I coat it?
Because the field of the roof was never the problem. A fiberglass roof still has a screwed-through metal flange at every vent, fan, and AC, each sealed with the same lap sealant on the same three-to-five year clock. Add gelcoat crazing with age and rigid-deck stress concentration at the cap transitions and you have the same leak list as everyone else.
Can it go over a roof I already coated with a liquid product?
Test it first. Work a putty knife under an edge and pull. If the old coating holds, clean, scuff, and prime over it. If it lifts in sheets, it all has to come off. Silicone-based roof coatings are the frequent problem case — silicone sheds subsequent coatings almost by definition.
Performance & Practicalities
What about water that ponds behind the AC?
Not an issue. The membrane is fully adhered with no seams and is not breathable, so standing water has nowhere to go but evaporate. Ponding becomes a dirt and debris question rather than a leak question. This is a meaningful difference from a single-ply roof, where a lap in a ponding area is a genuine risk.
Will hail damage it?
A 40–60 mil elastomeric membrane with 300–400% elongation absorbs impact rather than fracturing. Hail may dent the deck underneath; the membrane stretches over the deformation and stays watertight. Rigid coatings crack at the edge of the dent, which is where they then leak.
How much material will my roof need?
One gallon yields 1,604 mil-sq-ft at 100% solids — roughly 32 sq ft at 50 mil. A 200 sq ft towable roof runs 7–8 gallons for the field, plus material for the 80-mil build at every flange, cap transition, and termination. Send us length and width and we will do the takeoff.
Can I apply it myself?
Alasta Seal requires a plural-component proportioner with heated hose — Graco Reactor E-20/E-30 class or equivalent. It is not a roll-on or brush product, and it cannot be applied with an airless sprayer. If you do not have a rig we can refer you to an applicator or a mobile tech in your area.
Something Specific to Your Roof?
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