I’m replacing slideout wiper seals on my rockwood highhwall. Rockwood installed wiper only had 1/4" of the 1" adhesive seal over the fiberglass and attached with staples. So allowing 1/4" for fiberglass siding expansion, 1/2" wide aluminum bar takes up the rest of width and gives a surface to attach the new wiper seal to. 1/8" thick bar looks like thickness to bring up even with fiberglass. 1/16" aluminum bar and screws to secure the wiper seal. Does this sound right? Better methods or ideas?
Hello and welcome to the forum. This is difficult without a diagram, but I can say that not all staples are created equal. Perhaps a set of short machine screws or rivets would be better. We are asking quite a bit from this type of seal and if it is too tight it will bind.
From OpenAI:
Your idea is workable, but I doubt the exposed 1/4 inch was intentionally left for fiberglass expansion. It was more likely a fast production installation—the adhesive positioned the seal and the staples provided the actual retention.
A few suggestions:
- Verify that the 1/8-inch filler bar really finishes flush with the fiberglass and does not reduce slide clearance.
- Fasten into the aluminum or wood framing around the opening, not merely the thin fiberglass/luan skin.
- Bed the filler bar in butyl tape or a compatible non-hardening sealant so water cannot travel behind it.
- A 1/16-inch aluminum retaining strip over the seal flange should work. Tighten it only enough to hold the rubber; crushing the flange can distort or split it.
- Use stainless pan-head screws, isolate them from the aluminum with sealant, and seal every penetration. Avoid ordinary steel staples.
- Seal the top and side edges of the assembly, while preserving any intended drainage path at the bottom.
- Dry-fit everything and cycle the slide slowly before final sealing. Confirm that the wiper flips correctly in both directions and that the added thickness does not contact the slide-room trim.
Before fabricating the two-bar arrangement, I would also check whether a push-on, screw-track, or wider adhesive-backed seal matches the original profile. Those avoid putting extra holes through the wall. Seal manufacturers recommend matching the cross-sectional profile and thoroughly cleaning the bonding surface; they also show glue-on and mechanical attachment arrangements. Steele installation guidance and seal-selection overview.
So: the aluminum backing-and-retainer approach is reasonable if it is sealed, firmly anchored to structure, and clears the slide. I just would not base the dimensions on an assumed 1/4-inch siding-expansion allowance. A photo of the opening with the old seal removed would help confirm the exact arrangement.
Matt,
Thanks for responding. Two hours with AI brought together a pretty good picture and if its not correct may have a bigger problem later. First is that Rockwood uses vacuum bonded fiberglass so siding doesn’t need room for thermal expansion, it expands same as frame. The gap behind the wiper seal adhesive is because Rockwood the siding stops short of where the it supposed to be for the the adhesive strip to lay over the edge of siding. So I have on order 1/8" thick aluminum strips to shim to the correct position over 3/4" for seal that barely caught the edge of siding and 5/8" over on the other seal. Attaches to RV aluminum frame with 3m 4000 UV which will also waterproof edge of fiberglass and backing. Wiper seal attaches with adhesive strip then 1/16" thick hold down strip secured with #8 stainless screws dipped in 3m 4000 UV. Stripe sets under d-bulb. Finally GeoCel Flexpro Flexible to seal around top and exposed side of seal and reseal the plastic bottom trim. Have already secured rear siding to frame with 4000 UV and will do same for front panel before installing new wiper seal.
You could stock an entire hardware store with all of materials you are talking about. When you complete the project, please post a project summary, with a photo or two if you can, it will allow others leverage your findings. Thanks!