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noxinnhoj's avatar
noxinnhoj
Explorer
Mar 19, 2018

fantastik fan install/removal questions

I have a 2015 lance 915 with a fantastic fan,it has leaked on 2 different occasions.Just wondering if this is normal,no butyl tape was used and no screws around the flange on the original install,just self levelling sealant??I removed it and put a standard vent in,thanks

8 Replies

  • Method we use.

    Remove old vent or fan, remove old butyl tape and caulking.

    Clean area well with acetone (careful, it is hard on rubber roofs)

    Set fan and butyl tape in the sun to warm up.

    Drill holes about 6-8 inches apart all the way around fan flange if it doesn't have any. May want to do a dry fitting first to make sure you aren't putting holes over a cutout section of roof- sometimes the holes are slightly different sizes.

    Run strip of butyl tape on the bottom of the fan's flange and let it sit in sun with tape side up until it is soft.

    Install fan in hole, use smaller bit to predrill holes in roof through the holes in the flange. Helps prevent tearing the rubber roofing.

    Install and snug up all the screws. As it warms up, you can work your way around the flange and HAND TIGHTEN the screws just a little bit at a time to squeeze the butyl tape tight and squeezes out until the edge of the flange makes good contact with the roof.

    Use plastic edger to remove excess butyl tape.

    Use Dicor self-leveling or Eternabond to seal the edges and cover each screw head (EB Tape would be contiguous pieces to cover it all)

    Key things:

    1. Butyl tape must be WARM to squeeze it
    2. Do not strip any screws, you'll regret it later if they back out
    3. Seal edges AND screw heads/holes with caulking


    Hope this helps!
  • A Fantastic fan won't leak if installed correctly. Butyl tape or better is a polyurethane marine sealant under the wide flange. Any sealant *not* under the flange does little to keep water out, though it may make the owner feel better temporarily. Done right it will be leak free for a decade or two without additional maintenance.
  • no pre drilled holes in the plastic flange,i find that weird,i guess the guy I purchased it from did a bad install
  • Ours is under a Maxx-air cover, have never had a leak yet.
  • Self-leveling sealant doesn't work under the flange. That is what butyl tape is for.
    Put a lot of it on warm day, torque the screws and come back next day to re-torque and clean excess of butyl.
    You can caulk it for cosmetic reasons, but caulk on edge only will crack sooner or later.
  • Odd install- not normal. Was the foam gasket used that F/F provides?
    Along with screws, butyl under flange, then caulked.
  • My two Fantastic fans don’t leak...not a Fastastic issue. An installer issue.
  • Should have been installed with screws. If they're installed right they won't leak anymore than a standard vent.