Roof vent installation on high top van?

[Tkdplayer]

Has anyone cut through their high top roof on their van to install a a fantastic fan, etc? Is this a bad idea or not even big deal?

 

[highdesertranger]

putting a roof vent at your highest point is the most efficient place to put it. after all hot air rises so the hottest air is at the highest point. if you follow the correct installation process you will not have leaks. there are several threads on the subject. I would put it on top, just do it right. highdesertranger

 

[MikeRuth]

Seconds Highdesertranger.

 

[Almost There]

My high top is getting a roof vent asap but probably not until I get to do a cross border trip.

Insist on the installation crew using a high quality butyl tape and then silicone. Installed properly it should not leak.

I also won't be without a MaxxAir cover for it so that it can stay open in the rain. The cover also stops all the rattling most complain about in wind and when going down the road.

Sunroofs are notorious for leaking, roof vents are not.

Just to be on the safe side I never install a roof vent over a bed!

 

[One Awesome Inch]

I installed a Fantastic Fan a couple weeks ago in my standard cargo van. I recommend using Dicor Lap Sealant instead of silicone. What I did was use Eternabond, an excellent quality RV seal tape, around the edges of the vent. Then I used the Dicor on ALL of the edges of the Eternabond.

You can check out my youtube channel below where I did a full video on the installation.

 

[akrvbob]

Because the OP has a high top, I think the question is specific to fiberglass roofs. I know nothing about working with fiberglass so I didn't answer.

For you guys who are so much more knowledgeable than I, how hard is it to install a vent in a fiberglass roof?
Bob

 

[TMG51]

As far as I'm concerned there's no question, I would never go without installing a vent fan in the roof. I did so in my fiberglass high top although the hole was already there. I have cut holes in different areas of the top for different fan installs, though. I'm not shy with the caulking. Speaking of, I don't recommend silicone for sealing anything. I always use acrylic caulking (underneath the flange of the fan surround, and then around the perimeter and smoothed out).

The only thing I would posit to you as a concern is being careful of how strong your fiberglass top is and don't stand in the middle of it to do the install if it isn't strong enough. Some are.

If I had to cut the 14x14 hole new, I would mark it out, tape plastic hanging from the ceiling on the inside to catch sawdust (fiberglass is nasty), make 4 plunge cuts in the middle of my marks with a circular saw, and then finish the corners with a small tooth hand saw.

 

[Optimistic Paranoid]

I agree with highdesertranger and Mike Ruth.  I will add one caveat, though.

Even though it should never leak if it is done right, I would not position one over my bed, just in case.  If a leak SHOULD develop for some reason, ideally I would want to be able to temporarily deal with it by being able to put a pail under it.

To me, that's just simple good sense.  (I no longer refer to "common" sense for OBVIOUS reasons.)

Regards
John

 

[highdesertranger]

it's easy to install in a fiberglass top. single wall simply put some furring on the inside for the screws to grab into. screws do not grab good on fiberglass. if it's double wall you need furring between the two layers of fiberglass and more furring on the inside again for the screws. the furring between the fiberglass is to keep the fiberglass ridged so it won' crush when you tighten the screw. on the in between furring it's best to drill though holes to keep the screw from grabbing in this layer. most of the time the two layers are an inch or less apart. if you have foam sandwich fiberglass no need to put the furring between the fiberglass panes. if I didn't explain it goo enough let me know and I will go into more detail. highdesertranger

 

[66788]

The fiberglass is easier to work with than sheet metal.    Layout the square hole on the topside.   Drill 4  3/8 corner holes not exceeding your penciled out line at each corner.   Using a saber saw (jigsaw) cut the lines.    I made a square of 2" x 2" pine from Home depot (about $2.00), stained and varnished it and it came out nice.   It is nerve wracking to hack into your top for the first time.

I now have drilled over 40 holes in the top to mount solar panels, wiring, stainless steel eye bolts to quick clip 90% shade mesh to, and other needs.   Each is properly sealed and will not leak.   Dicor is great stuff.

 

[debit.servus]

After one year, I finally ordered a FANTASTIC FAN from ADVENTURERV.com. It is going into the fiberglass high-top on the van. The reason it took so long is because of not having the m-o-n-e-y. A $200 van mod is a big thing for me.

1: Is a wooden frame mandatory inside for screwing into, or can I get away with drilling into fiberglass (forming pilot holes before the screws go in of course)? I believe the fiberglass high-top is 1/4 to 1/2 inch thick.
2: There is no place to for water to pool on all sides, but there is a slight curve, could I get away with using butyl tape on the fiberglass? I have some KWIK SEAL that would be nice to use up, could that be used to seal the screw heads? Or should I acquire the DICOR sealant?
3: What is the set time of the sealant and butyl tape?
4: Is there any special prep before applying the butyl rubber to the top of the fiberglass hightop? Plan to clean the surface with rubbing alcohol.

 

[highdesertranger]

there should be instruction with the vent. do not screw into the fiberglass with wood or sheet metal screws. the fiber glass will crack. you could use bolts with washers or use wood furring. if you go with the wood furring you can use wood screws. drill the holes though the fiberglass a little larger than the wood screw, you don't want the wood screw biting into the fiberglass but into the furring.

as for the butyl tape there is no cure time it's ready to go as soon as the vent is screwed down. we used to use paint thinner to clean the surface before the tape, but alcohol should work. make sure you get high quality butyl tape there is a wide range of quality when it comes to tape. I have a link for good tape I will see if I can find it later.

nowadays they usually Dicor around the flange as a double seal. hope this helps. highdesertranger

 

[OpenSpaceman]

Has anyone cut through their high top roof on their van to install a a fantastic fan, etc?  Is this a bad idea or not even big deal?

I have two fantastic fans in my fiberglass roof. I sealed it with butyl tape I think it's called, per the manufacturers instructions. No leaks in two years of super hard rain storms and tons of snow.

*I could not live comfortably in my van without it. In the summer of course... but more importantly in the winter...my forward vent is open all the time when I have my Mr. Buddy heater on. It sits right below it.

Not sure but aren't a lot of RV's roofs fiberglass? at least the C class ones?

 

[Binxie]

I have two fantastic fans in my fiberglass roof.

I have two Fantastic Fans in the sheet metal roof of my mini utility van, with vent covers, one behind the front seats and the other near the back where my head rests on the pillow. I love the arrangement for complete ventilation for myself and for when I have the dogs in the van and I'm in a store or whatever. In hotter or super-humid weather, I can run one fan in and one fan out for fast circulation of all air.

At times when the air is just a bit stuffy, I have one fan pushing air out and the other vent just opened. With the windows closed, the fan pushing out pulls in fresh air through the other open vent, right onto my face -- bugs are screened out, yet I have excellent airflow and maximum comfort.

 

[johnny b]

When getting ready to cut, use 1.5 or 2 inch masking tape both inside and out. This will minimize any splintering and reduce a little bit of the dust.

 

[MrBob]

Has anyone cut through their high top roof on their van to install a a fantastic fan, etc?  Is this a bad idea or not even big deal?

 
Can you think of a single fiberglass boat that doesn't have holes cut or drilled through the glass to mount hardware? Cut away. Fiberglass is notoriously hard on blades so use a new one. If you use a jigsaw, use a blade with a higher number of teeth for a finer cut. As has been mentioned, lay masking tape along your cut line and make your marks and cut on the tape. If you're worried about scratching your finish, also tape the shoe of the saw. Drill holes in the corners of your layout for the blade to fit through - easy peasey. If you take your time with a tape measure and Magic Marker it's a fairly simple job.
 When I installed my powered roof vent I cut open a trash bag and taped it to the ceiling under my work area so it caught all of the chips.
 I've been looking at the Fantastic fans to replace my POS Heng unit but someone here mentioned Maxx Air fans and they're looking even better for the same price.

 

[MrBob]

there should be instruction with the vent.  do not screw into the fiberglass with wood or sheet metal screws.  the fiber glass will crack.  you could use bolts with washers or use wood furring.  if you go with the wood furring you can use wood screws.  drill the holes though the fiberglass a little larger than the wood screw,  you don't want the wood screw biting into the fiberglass but into the furring.

as for the butyl tape there is no cure time it's ready to go as soon as the vent is screwed down.  we used to use paint thinner to clean the surface before the tape,  but alcohol should work.  make sure you get high quality butyl tape there is a wide range of quality when it comes to tape. I have a link for good tape I will see if I can find it later.

nowadays they usually Dicor around the flange as a double seal.  hope this helps.  highdesertranger

  I've done quite a bit of work on boats and I've installed about a million screws into fiberglass after drilling the proper pilot hole, so I guess I've had a different experience. I don't know how thick his roof material is but if it's in the 3/32"  range he should be fine with 3/4", #8 stainless steel screws installed about every 3" or 4".
 We do use backers when installing some fittings onto boats to provide extra meat for the screw threads.
 The Butyl tape will provide lots of stiction to keep everything in place.

 

[debit.servus]

  I've done quite a bit of work on boats and I've installed about a million screws into fiberglass after drilling the proper pilot hole, so I guess I've had a different experience. I don't know how thick his roof material is but if it's in the 3/32"  range he should be fine with 3/4", #8 stainless steel screws installed about every 3" or 4".

This part of the high-top as I remember was 1/4 inch thin. Looks like puitting in a roof fan took alot of structural stregnth away, but worth it for the always-there ventalation.

I piloted holes in the center for future screwing. This vent was installed on a curved bulkhead which meant creative sealing. I didn't screw the vent down.


If one can't afford a FANTASTIC FAN in vent, acquire just a vent and install that for as low as $50. The fan can be bought later, and installed in the vent.

There are two spots selected for future vents on the flat part of the high-top. Planning at least one clear dome over the bed to view the stars at night, and stream natural light in during the day.

 

[MrBob]

This part of the high-top as I remember was 1/4 inch thin. Looks like puitting in a roof fan took alot of structural stregnth away, but worth it for the always-there ventalation.

I piloted holes in the center for future screwing. This vent was installed on a curved bulkhead which meant creative sealing. I didn't screw the vent down.


If one can't afford a FANTASTIC FAN in vent, acquire just a vent and install that for as low as $50. The fan can be bought later, and installed in the vent.

There are two spots selected for future vents on the flat part of the high-top. Planning at least one clear dome over the bed to view the stars at night, and stream natural light in during the day.

 I got up close to a Maxx Air 12v roof vent the other day and I was impressed with the quality of the construction. 

 My first roof vent was one of the 9" by 9" units and I think I paid around 20 dollars, for it so a vent can be had quite inexpensively, and it's easy to upgrade to the 14" unit in the future. Having a vent in that rear area really makes a difference.

 

[Tkdplayer]

I'm finally installing the maxxair vent on my fiberglass hitop roof. Does it really matter if I use putty or butyl tape? I still have a lot of putty tape from when I installed the fantastic vent on my metal roof last year.