Fan-tastic install question: caulk, butyl, or other...? - Fiberglass RV

Thread Tools Search this Thread Display Modes
Old 07-06-2013, 06:06 PM   #1
Name: geoff
Trailer: bigfoot
Posts: 38
Fan-tastic install question: caulk, butyl, or other...?

Hi everyone,

I have purchased a new Fan-tastic 6600 to install in our 1981 Bigfoot. The instructions say to caulk between the roof and the fan. Should I use a silicone caulk, or should I use butyl tape? Or other suggestions to seal it?

And can I stand on the roof...? I'm only 140lbs, but I don't know how strong 30 year old fiberglass is. I may just look for a piece of plywood to lay on the roof in hopes that it will spread my weight out.

I have a roll of butyl tape as I need to re-seal the back window as well.


spartacus is offline   Reply With Quote
Old 07-06-2013, 06:24 PM   #2
Senior Member
Name: bob
Trailer: 1984 u-haul ct13; 1996 Casita 17 Spirit Deluxe; 1946 Modernistic teardrop
New York
Posts: 3,704
Use the butyl tape!! When I did the fantastic Fan install on our Uhaul I was lucky that I have one of those rolling stairs things that is 5' tall. If you use a ladder remember that leaning over the trailer roof may take weight off the ladder feet and let it slide out. A helper to hold the ladder is a good idea. I didn't get on the roof, moved stairs from one side to the other a couple times.

mary and bob is offline   Reply With Quote
Old 07-06-2013, 06:27 PM   #3
Senior Member
Name: Linda
Trailer: '77 Scamp
Posts: 630
Definitely don't use silicone. Use the butyl tape overlapping at each corner. I used a non silicone caulk to seal around the peremeter after the install and put a little blob of caulk over each screw. I'm just that way... extra careful. You'll love the new fan. I wouldn't stand on the roof. Can you reach the fan area by leaning over the roof from a good step ladder? That's what I did but I just have a 13'. Putting plywood is a good idea if you can't reach by leaning over. Good luck on the install.
Otters is offline   Reply With Quote
Old 07-07-2013, 05:51 AM   #4
Senior Member
Ron F's Avatar
Name: Ron
Trailer: Eggless for now.
Formerly NH, now full timing
Posts: 405
I've installed several Maxx Fans, similar to Fantastic. They recommend using butyl tape between the roof and the flange, then using Dicor 501 to put a dab of sealant over the screw heads that fasten the unit to the roof to seal around the screw head.

I don't stand on the roof. Most of these trailers are lightweight for a reason, that being that the fiberglass is not that thick. But, with a Bigfoot, you may be able to get away with it. A piece of plywood would certainly help mitigate any potential problems.
Ron F is offline   Reply With Quote
Old 07-07-2013, 06:27 AM   #5
Senior Member
Name: Dave
Trailer: '78 Trillium 4500
British Columbia
Posts: 150
DON'T stand on the roof, they aren't strong enough and will likely delaminate under the weight. I could reach the vent on our BF stretching from a ladder and leaning on a bench cushion helped.
Dave_L is offline   Reply With Quote
Old 07-18-2013, 05:01 AM   #6
Junior Member
Name: Jan
Trailer: Boler 1978
Posts: 15
When we got our Fantastic Fan, it was recommended to use butyl tape instead of the foam sheet material that came with the fan. That stuff might work if you have a perfectly flat roof. I did overlap the ends and cleaned up the butyl tape that oozed out after a few days. It nicely oozed down into the gap when seen from the inside of the Boler. It's been really hot here and I think that helped.

We've had some heavy rains several days right after fan installation and there was no sign of leakage.

I bought another 13' ft multi-use ladder (the ones that you can adjust and fold into several different configurations). That really helped during installation because I could quickly work on both sides of the Boler without having to trundle the ladder to the other side. And it allowed me to reach over the centerline of the roof easily enough and maintain my balance safely despite my short arms.

Hope this helps....

Winfield456 is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Where to buy Butyl Caulk? D Davis Problem Solving | Owners Helping Owners 18 03-20-2013 02:43 PM
Best Butyl caulk? Craig D. Thompson Care and Feeding of Molded Fiberglass Trailers 7 02-25-2012 07:02 AM
Fan-tastic Fan Seller - Best Price I Found barryra General Chat 1 07-11-2011 04:51 PM
Butyl tape vs. butyl caulk- newbie looking for input Jason, M Problem Solving | Owners Helping Owners 9 08-11-2008 02:57 PM
Fan-Tastic Vent Speed Mod Patrick M. Modifications, Alterations and Updates 7 03-05-2008 11:40 PM

» Upcoming Events
No events scheduled in
the next 465 days.
» Virginia Campgrounds

Reviews provided by

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 09:33 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.