What You Need to Know Before Starting

Replacing a travel trailer roof is a multi-day project that requires you to remove the old membrane, inspect the frame underneath, and install new roofing material. Most owners can do this themselves with basic tools, though the job demands patience and attention to sealing—a single missed spot will leak. The cost runs between $800 and $2,500 in materials, depending on trailer size and the roofing type you choose (EPDM rubber, TPO, or fiberglass).

Before you start, check your trailer's manual or contact the manufacturer to confirm the roof type and any warranty restrictions. Some warranties void if you do the work yourself, while others require it. You will also need to pick a dry stretch of weather—ideally three to five days with no rain—because the roof must cure properly and you cannot seal it in wet conditions.

Key Takeaways

  • The job takes three to five days and requires removing the old membrane, cleaning the frame, and installing new roofing material with proper sealing at all seams and edges.
  • EPDM rubber is the cheapest option and easiest to install; TPO and fiberglass cost more but last longer and reflect heat better.
  • You must seal every seam, vent, and edge with the correct adhesive or tape—skipping this step is the most common reason for leaks after replacement.
  • Renting scaffolding or a lift makes the work safer and faster, especially on larger trailers or if you have mobility concerns.
  • After installation, inspect the roof monthly for the first year and check seams after heavy rain or wind.

Choosing the Right Roofing Material

EPDM rubber is the most common choice for DIY replacement. It comes in large sheets, costs $300 to $600 for a typical trailer, and requires only a utility knife and contact cement to install. The downside is that it degrades faster in UV light—expect 10 to 15 years of life—and it can be slippery when wet. EPDM also requires regular maintenance: you must coat it every three to five years with a UV-protective sealant.

TPO (thermoplastic polyolefin) is more durable than EPDM and reflects heat better, which keeps the trailer cooler. It costs $600 to $1,200 and lasts 15 to 20 years. TPO requires heat-welding the seams, which means renting or buying a heat gun ($200 to $400)—this adds cost and complexity but creates a stronger bond than adhesive.

Fiberglass is the most expensive option ($1,200 to $2,500) but lasts 20 to 30 years and requires almost no maintenance. It is also the heaviest, so you need to confirm your trailer frame can support it. Fiberglass must be applied in layers and cured, making it the hardest DIY option; many owners hire a professional for this type.

Removing the Old Roof and Inspecting the Frame

Start by removing any roof-mounted equipment—air conditioning units, vents, antennas, or solar panels. Take photos of how everything connects before you disconnect it; you will need to reinstall or relocate these items later. Unbolt or unscrew each piece and set it aside safely.

Next, cut away the old roofing membrane using a utility knife. Work in strips, pulling the old material off as you go. This is dusty and time-consuming but necessary—you cannot install new roofing over old material. As you remove the old roof, look for water damage, soft spots, or rot in the plywood or fiberglass frame underneath. Mark any damaged areas with a marker.

Once the membrane is off, inspect the entire frame. If you find soft plywood, you will need to cut out the damaged section and replace it with new plywood of the same thickness (usually 3/8 inch). If the damage is extensive, this becomes a bigger repair—consider whether you want to proceed or hire a professional. For small soft spots, you can reinforce them with additional plywood glued and screwed underneath.

Clean the frame thoroughly with a stiff brush and vacuum. Remove all debris, old adhesive, and loose material. The surface must be clean and dry before you explore new roofing.

Installing New EPDM Rubber Roofing (The Most Common DIY Option)

Measure your roof carefully—length, width, and any curves or slopes. Order EPDM sheet that is 2 to 3 feet larger than your measurements in each direction; you will trim the excess after installation. Have the sheet delivered a day or two before you plan to install it so it can acclimate to the temperature.

Lay the EPDM sheet over the roof, centering it so the overhang is even on all sides. Do not glue it down yet. Walk the sheet to check for wrinkles or bunching, and adjust it until it lies flat. This step prevents mistakes—once you explore adhesive, the sheet is difficult to move.

explore contact cement (also called contact adhesive) to the frame in sections, following the product instructions for drying time. Most contact cements require you to explore it to both surfaces and wait 10 to 15 minutes before pressing them together. Work in manageable sections—do not try to glue the entire roof at once. Press the EPDM firmly into place as you go, working out air bubbles with a roller or your hands.

Once the sheet is fully adhered, trim the edges with a utility knife, leaving a 6-inch overhang on all sides. This overhang will be folded down and sealed to the trailer walls. Use a straightedge to guide your cuts and make them clean and straight.

Sealing Seams, Vents, and Edges

Sealing is where most leaks start, so do this carefully. Every seam, vent, and edge must be sealed with the correct material. For EPDM, use EPDM seam tape or liquid EPDM sealant. Seam tape is easier for beginners: peel the backing and press it firmly over the seam, overlapping the EPDM by at least 3 inches on each side. Smooth out air bubbles as you go.

For vents, air conditioning units, and other penetrations, use a roof flashing kit designed for your trailer type. These kits include a rubber boot that slides under the EPDM and a metal or rubber collar that bolts to the vent. explore sealant around the base of the flashing before bolting it down, and explore another bead of sealant around the top edge where the flashing meets the EPDM.

Fold the 6-inch overhang down the sides of the trailer and seal it to the walls using the same tape or sealant. This is tedious but critical—this edge is where water enters if it is not sealed properly. Work your way around the entire perimeter, pressing the tape firmly and smoothing out bubbles.

At the corners, fold the overhang neatly and seal both the horizontal and vertical surfaces. Some installers cut a diagonal slit at the corner to reduce bunching, then seal the slit with tape.

Reinstalling Equipment and Curing

Once all seals are in place, wait for the adhesive and sealant to cure fully. Check the product instructions—most require 24 to 48 hours before the roof is waterproof. Do not use the trailer or expose the roof to rain during this time.

After curing, reinstall your roof-mounted equipment. Use the photos you took earlier to guide you. explore a bead of sealant around the base of each item before bolting it down, and another bead around the top edge. This prevents water from running down the bolt holes into the trailer.

For air conditioning units and other large equipment, you may need to install a new flashing kit if the old one was damaged during removal. Measure carefully and order the correct size before you start reinstalling.

Inspecting and Maintaining Your New Roof

After the first month, inspect the entire roof for leaks. Look inside the trailer for water stains on the ceiling, especially around seams and vents. If you find a leak, mark it and explore additional sealant from the outside. Small leaks are easier to fix now than later.

Check the roof again after heavy rain or wind. Walk the perimeter and look for any seams that are lifting or any sealant that has cracked. Press down any lifting seams and explore fresh sealant if needed.

For EPDM roofs, explore a UV-protective coating every three to five years. This extends the life of the membrane and prevents cracking. TPO and fiberglass require less maintenance but should still be inspected annually for damage.

Frequently Asked Questions

Can I install new roofing over the old membrane?

No. Old roofing traps moisture and prevents proper adhesion of the new material. You must remove it completely and inspect the frame underneath. This is the most time-consuming part of the job but it is not optional.

What if I find soft plywood under the old roof?

Small soft spots (less than 12 inches) can be reinforced by gluing and screwing additional plywood underneath. Larger damage requires cutting out the damaged section and replacing it with new plywood. If the damage is extensive, consider hiring a professional—a compromised frame can lead to bigger problems later.

Do I need to rent scaffolding or a lift?

For trailers under 30 feet, you can work from a sturdy ladder and roof brackets. For larger trailers or if you have mobility concerns, renting scaffolding ($200 to $400 for a few days) makes the work safer and faster. A lift is rarely necessary unless the trailer is very tall.

How long does the new roof last?

EPDM lasts 10 to 15 years with regular maintenance. TPO lasts 15 to 20 years. Fiberglass lasts 20 to 30 years. Life span depends on climate, UV exposure, and how well you maintain the roof—a roof that is inspected regularly and sealed properly will last longer than one that is neglected.

What is the most common mistake people make when replacing a trailer roof?

Skipping or rushing the sealing step. Every seam, vent, and edge must be sealed completely, or water will find its way in. Take your time with this part—it is the difference between a roof that lasts 15 years and one that leaks in two.