One flat bulb seal, three seasons, and a travel trailer subfloor mapped before cutting

Consider this a representative composite. The failure chain, the measurements and the additions to the estimate are typical of slide seal water intrusion, and no specific owner, trailer or claim appears anywhere in it.

A 31 ft travel trailer with a single flush floor slide came in over a soft patch of about a square foot in front of the slide opening. Nothing else about the trailer suggested a problem, which is normal for this failure and is why it usually gets found by a heel rather than by an inspection.

Plywood laminated to a steel frame loses stiffness before it loses shape and long before it looks wrong from underneath. A crawl under the trailer with a torch finds nothing. A meter finds it immediately, which is why the meter comes out before the saw does.

The source was a single compressed bulb seal on the leading edge of the slide. Bulb seals work by touching the sidewall with light pressure along their whole length. This one had taken a set, gone flat over roughly two feet, and stopped touching the wall entirely at the bottom of that run. Slide out seal replacement prices at $400 to $3,000 across 2 to 14 hours, and the rubber itself is the cheapest part of that number.

A seal that no longer touches does not leak dramatically. It admits a film of water whenever rain arrives from the right direction, down the inside face of the slide, onto the deck edge, under the flooring. Three seasons of that is not a flood. It is slow repeated wetting with drying in between, which is the exact cycle that destroys an adhesive bond and delaminates a laminated deck.

The witness line on the sidewall told the story before anything came apart. Where a seal touches, it leaves a mark. Where the mark stops, the seal stopped.

Cutting a subfloor to find the edge of the damage is how a small repair becomes a large one. The area was mapped first: meter readings on a grid at six inch centres, running from the slide opening out into dry floor in every direction, with the readings written onto a plan and photographed alongside it.

The wet footprint ran about four feet along the slide opening and just under three feet into the room, well past the square foot a heel could feel. It also ran into the wall bottom on the hinge side, which the floor plan of the trailer made likely and which nothing visible confirmed.

Flooring and subfloor replacement prices against $500 to $8,500 at 4 to 35 hours, and where a job lands inside that band is decided almost entirely by how far the map goes before anybody starts cutting.

Flooring up, then deck cut back to sound material along a joist rather than to the edge of the wet reading, because a butt joint over air is a future soft spot with a date on it. The deck laminate had released from its frame across most of the mapped area and the core had lost stiffness with no visible rot, which is the normal presentation and the reason a visual check under a trailer finds nothing worth reporting.

The wall bottom plate on the hinge side had wicked and was replaced for about five feet. One floor joist was surface stained and structurally sound, so it was dried, photographed and left alone.

Removing what is not damaged is as much a failure as leaving what is. It just fails in a direction that looks like diligence on an invoice, which is why the joist that stayed is recorded in the file with the reason it stayed.

The first estimate was written from the soft spot and priced a small deck patch with flooring over it. That is what the visible evidence supported, and it was written in good faith by somebody working from a heel test.

The moisture grid arrived two days later and doubled the deck area, which became the first supplement. The wall bottom plate arrived on day six with the wall open, which became the second. Each addition cost days as well as dollars, and the days came from review rather than from work.

Water damage, delamination and soft spot repair prices against $750 to $18,000 plus at 5 to 80 hours, and this job ran 26 to 58 hours. The lower half of that band exists for the version of this job that gets caught before a wall is involved.

New deck bonded and mechanically fastened to the frame, wall bottom plate replaced, flooring laid, and the slide seal replaced along its full run rather than only across the flattened section. Then the slide was cycled and adjusted so the new seal makes even contact top to bottom, because a seal fitted to a slide that is out of adjustment flattens again inside a season and starts the whole chain over.

Then a water test, because reassembly is not a result. The room is run out, the seam is wetted deliberately and progressively rather than blasted, and the interior is watched and metered instead of glanced at. Slide travel, sync and seal integrity all get checked before delivery.

The closing readings went into the file next to the intake readings. Two sets of numbers on the same grid is the only way somebody later can see that the floor went back dry rather than merely covered.

Nothing here was careless. A compressed bulb seal is invisible from outside, and a slide that runs in and out normally gives nobody a reason to look at it. The sequence is still worth stating plainly, because every stage of it was cheaper than the stage after it.

The seal flattened. Then it stopped touching. Then the deck edge got wet on a cycle. Then the bond released. Then a heel found it. A seal replaced at the flattened stage lives near the bottom of the $400 to $3,000 seal band. The same failure three seasons later reached deck, flooring, a wall bottom plate and slide adjustment hours.

• Walk the slide seal with the room out twice a year, pressing along the bulb by hand and looking for a run that stays flat.
• Find the witness line on the sidewall where the seal contacts, and treat a broken or missing line as a leak already in progress.
• Meter the floor at the slide opening once a season, room in and room out, and keep the numbers rather than the impression.
• Run a hose along the closed slide seam after any seal work and watch the inside rather than the outside.

The job cleared $2,000, so a 50 percent deposit applied at authorisation. It did not clear $10,000, so the further 25 percent at parts arrival did not apply. Sales tax of 7.75 percent applied to parts and materials, labour was untaxed, and a card payment above $1,000 carried the 3.5 percent surcharge. Nothing at this shop prices below $500, which matters on a job whose smallest line is a length of rubber.

Elapsed time was about three weeks. Detail labour posts at $95 per hour and was used only to clean up the interior after the flooring went in, which is the kind of line owners are surprised to see itemised rather than absorbed.

The file now holds the intake moisture grid, the teardown photographs, the boundary the deck was cut to and the reason for it, the joist that stayed and why, the water test readings and the delivery set. A trailer with that behind it sells differently from a trailer with a patch in the floor and a story, and the difference is documentation rather than persuasion.