Adding roof anchors for kayaks (ratchet strapped to the top)

[ErikTande]

I hauled 2 kayaks a couple years ago on my roof and used the railing at the back to anchor them down, but it was a little flimsy for my taste.  I had to re-attach it in a couple places where it started to pull up and re-seal it.

Is the top of the roof plywood?  Can I just screw in some beefy eye hooks anywhere and seal them up?  I'll post a picture of the roof later, it's a 1985 p30 Fleetwood Southwind.  You can see the railing that I mostly used in this pic:

[ClydesdaleKevin]

If you want a very strong anchor point on the roof, make sure you put your eyebolts or sailing cleat screws (and a lot of other awesome marine application lashing systems) into the trim panel on the SIDES of the RV, where the roof meets your sidewalls.  That is the strongest place to put anything like that on an RV roof.  Which is why that is where they attach the awning moulding to that area. 

Kev

[Rickf1985]

The roof is generally a this, and I mean VERY thin aluminum sheet over top of luann and foam. Basically the same as the sides with the addition of the aluminum. It will not hold anything like that eye bolt. The structural beams are lightweight steel, think the same as the stuff they use in drywall construction in houses nowadays, again, will not hold. The edges are iffy, in the older ones they had a solid wood beam but the newer ones had the same flimsy thin metal with reinforcement points where needed. You would need to get the structural drawings for that coach to see where the hard points are. Or find one in a junkyard that has been stripped.
When I say the aluminum roof is thin, I was scraping old sealer off of mine with a putty knife and I cut right into the roof! It is I would guess no more than 20 gauge.

[tmsnyder]

There must be some rafters up there, no?   


BTW I always wondered if the standard roof vent is 14" in order to fit into the space between a standard 16" OC raftered roof

[TerryH]

I agree with Rick. The eye screw in your photo would be asking for trouble.
Depending on the type of headliner you have it is sometimes easy to find where the side to side ribs are - where the headliner joints are.
A stud sensor may help. They measure change in density.
Regardless, I would go with a machine thread - 1/4 x 20, 5/16 x 18 - with nuts, lock washers, flat fender washers, backing plate inside and outside to sandwich the roof. Lots of properly applied polyurethane caulking.
The interior fastening may be able to be hidden inside cupboards, depending on your coach layout.
You can determine your roof thickness from a vent.
My opinion of the class A roof racks is that the stanchion anchoring is one of the most common causes of roof leaks. Right up there with front clearance lamps.
Further, without structural drawings I would be reluctant using a side wall fastening. From your photo it appears your awning channel is considerably lower than the side wall to roof joint. I would really want to know exactly what is behind there.

[Rickf1985]

I can tell you that on my awning there is a crushed wall! Top and bottom mounts are mashed. They did not care when they put that stuff on, it worked good for the ten years people were expected to own it. When things started to leak they got rid of the coach and someone else had to deal with it and that is when they found out about the shoddy workmanship.

[ClydesdaleKevin]

In my opinion, since kayaks don't really weigh diddly squat, you should be just fine if you put your anchor points where your sidewalls meet your roof, on the sides.  I would use something like sailing cleats with stainless screws...and make sure you put a good sealant under them, in the holes you drill, and thickly all over the threads.

Alternatively, you COULD glue down mounting points, or use a combo of glue and screws, like I did with my solar panel mounts.  This Chemlink M1 sealant is about the strongest stuff you can get, and my panels aren't going anywhere, even in high winds on the highway.

This link is the cheapest place I've seen to get this stuff.  Again, you want the Chemlink M-1 sealant.  It says it is green in the description, but when I used it, it looked more greyish/white to me.

https://www.bigrocksupply.com/Adhesives.html

Kev

[Rickf1985]

A kayak may be light but think about this, you are traveling down the road at 60 MPH and hit a 45-50 MPH head wind or gust. That is 105-110 MPH of wind pushing on that kayak and I can assure you that is more than enough to pull an anchor out if it is not really, REALLY secure! We had a member on here a few years ago that lost most of his roof while driving down the road in a strong gust. Totally the RV, I don't think he ever did get another. Can't remember his name, he trailered horses all around.


His username was eXodus

[ClydesdaleKevin]

A kayak may be light but think about this, you are traveling down the road at 60 MPH and hit a 45-50 MPH head wind or gust. That is 105-110 MPH of wind pushing on that kayak and I can assure you that is more than enough to pull an anchor out if it is not really, REALLY secure! We had a member on here a few years ago that lost most of his roof while driving down the road in a strong gust. Totally the RV, I don't think he ever did get another. Can't remember his name, he trailered horses all around.


His username was eXodus

He's not putting a Chris Craft up there...lol!  But again, use the M-1 sealant instead if there is concern...or stainless screws and the M-1 sealant like I did with my solar panels.

Heck...he might even be able to find Yakima or Thule rack feet/towers that are flat on the bottom (the kind used for gutterless cars) and glue THOSE down to the roof with the M-1 sealant.  Then he would have the option of using Yakima or Thule crossbars with actual no-crap kayak carriers and never have to worry about it again.  You can find used Yakima and Thule towers on eBay and Craigslist CHEAP...especially if they are missing their keys (which you wouldn't have to worry about with an RV roof mount). 

Kev

[TerryH]

I hauled 2 kayaks a couple years ago on my roof and used the railing at the back to anchor them down, but it was a little flimsy for my taste.  I had to re-attach it in a couple places where it started to pull up and re-seal it.

As you wrote the roof rack stanchion to roof fastening failed for your intended use.
Do you really want to copy that failed system again?

[DeDONRAGE]

https://www.rvkayakracks.com/