Resealing an RV roof with SEMCO Liquid Membrane typically runs about $300 to $350 in materials for a 200 to 250 sq ft trailer roof (two coats at roughly 200 sq ft per gallon, plus Fabric Reinforcement at the seams, vents and end caps). Replacing the same roof outright typically costs $5,000 to $15,000 or more in materials and labor, depending on whether it's rubber/EPDM, fiberglass, TPO, or aluminum. If the decking underneath is still sound, with no soft spots or rot, resealing is almost always the cheaper first move, and SEMCO's product warranty covers mobile and RV applications.
This guide covers what a full roof replacement actually costs by material, when resealing makes sense instead, a real materials cost breakdown for doing it yourself, and how it compares to other recoat approaches.
In this guide
- How much does it cost to replace an RV roof?
- Can you reseal an RV roof instead of replacing it?
- What does it cost to reseal with SEMCO Liquid Membrane?
- Comparing your options
- FAQ
How much does it cost to replace an RV roof?
Full replacement cost depends heavily on the roof material and whether you hire it out or do it yourself. Professional labor is usually included in the ranges below:
| Roof material | Typical full replacement cost | Notes |
|---|---|---|
| Rubber or EPDM | $5,000 to $9,000+ | Most common; can still tear, leak or degrade over time |
| Fiberglass | $9,000 to $15,000 | Higher cost; more complex to install |
| TPO | $6,000 to $12,000 | Energy efficient, UV resistant |
| Aluminum | $6,000 to $10,000 | Less common; corrosion resistant |
DIY installation can reduce the labor portion of these numbers, but full roof replacement is a bigger job than resealing: it usually means stripping the old roofing material down to the decking, which is where most of the cost and risk lives.
Can you reseal an RV roof instead of replacing it?
In most cases, yes, as long as the decking underneath is still structurally sound. Before resealing, press-test the roof for soft spots and check for rot; a reseal only works if what it is bonding to is solid. If the decking itself has failed, that is a structural repair, not a coating job, and resealing over it will not fix the underlying problem.
Once the decking checks out, prep depends on the roof's history:
- Roof has never been coated: clean with Power Cleaner, then Stone Soap (Prep B).
- Roof has been coated before, or you're not sure what was used: clean with Power Cleaner, then Nu-Lift Cleaner (Prep C), since mixing an unknown existing coating's chemistry with a new one is a common cause of bond failure.
No primer is needed on EPDM, TPO, fiberglass or aluminum. That is a real practical difference from many rubber-based recoat systems, which often call for a separate primer coat on EPDM or TPO before application, adding a step and a cost. SEMCO Liquid Membrane also stays flexible under an RV's constant road vibration and temperature swings; see Full-Time RV Living Requires Full-Time Protection for why that flexibility matters more than rigidity on a roof that moves every time you drive.
What does it cost to reseal with SEMCO Liquid Membrane?
Here is a real materials breakdown for a roughly 240 sq ft roof (about an 8 by 30 foot single-axle travel trailer), at the standard 2 coats, 200 sq ft per gallon rate:
| Item | Quantity | Price |
|---|---|---|
| SEMCO Liquid Membrane (1 Gallon) | 2 gallons, covers about 400 sq ft at 2 coats | 2 × $113.75 = $227.50 |
| Fabric Reinforcement (6" x 75 ft) | 1 roll, for vents, seams and end caps | $60.15 |
| Power Cleaner or Nu-Lift Cleaner (1 Quart) | 1 quart, for prep | $23.65 to $27.30 |
| Estimated total | Roughly $310 to $320 |
Measure your own roof and check the live coverage calculator on the product page before ordering. A previously coated or more porous roof can need a third coat, which changes the quantity.
Apply out of direct sun between 50 and 85°F, and give it a minimum 7-day cure before heavy rain, washing or long-term storage; longer in cool or humid weather. A resealed roof also tends to show better at resale time than one with visible patches or UV damage; see Increase Your RV's Resale Value with SEMCO Liquid Membrane Waterproofing. If you're timing this job right before putting the RV away for the season, see Resealing Your RV Roof Before Winter Storage for the water-based vs rubber-based tradeoffs specific to that timing.
Comparing your options
| Approach | Primer needed | Cure before use | Materials cost (~240 sq ft roof) |
|---|---|---|---|
| Full roof replacement | N/A | N/A | $5,000 to $15,000+ |
| Rubber-based recoat product | Often yes on EPDM/TPO | Varies by product | Primer sold separately, adding a step and cost |
| Silicone-based recoat product | Sometimes | Varies by product | Dries harder and less flexible once fully cured |
| SEMCO Liquid Membrane (water-based) | No | 7 days minimum | About $310 to $320 |
Single-component, water-based liquid waterproofing membrane. No primer needed on EPDM, TPO, fiberglass or aluminum. 1,300% elongation, 14 g/L VOC.
Reinforcing fabric bedded into wet membrane at vents, seams, end caps and skylights.
Frequently asked questions
Do I need a primer to reseal an RV roof with SEMCO Liquid Membrane?
No. It bonds directly to EPDM, TPO, fiberglass, aluminum and most existing coatings once the surface is properly prepped and cleaned. No separate primer step.
How long before I can drive or store the RV after resealing?
It's dry to the touch in 1 to 2 hours and recoatable the same day. Give it a minimum 7-day cure before heavy rain, washing, or long-term storage, longer in cool or humid weather.
Will resealing instead of replacing affect my RV's warranty?
That depends on your RV manufacturer's own roof warranty terms, which SEMCO can't speak to. SEMCO's own product warranty (5-year standard, with mobile and RV applications covered) applies to the membrane itself, separate from any factory roof warranty.
Can I reseal over a roof that's already been coated with something else?
Yes, but the prep is different: clean with Power Cleaner, then Nu-Lift Cleaner, since the existing coating's chemistry is often unknown. Skipping this step, or recoating over a fully cured membrane without re-prepping it, is the most common cause of a reseal failing to bond.
What's the real materials cost for a typical single-axle travel trailer roof?
For roughly 200 to 250 sq ft, expect about $300 to $350 in Liquid Membrane, Fabric Reinforcement and cleaner, against $5,000 or more to replace the same roof outright.
Ready to reseal your RV roof?
SEMCO Liquid Membrane is a single-component, water-based liquid waterproofing membrane built for DIY application, with no primer needed on EPDM, TPO, fiberglass or aluminum.
Shop SEMCO Liquid Membrane →Free shipping on orders over $99 (48 contiguous states).
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