[radley]

I'm installing a Maxxair 7500K Deluxe and I'm about half way through. I'm using one of the Impact 3D (Hein) adapters and I'm about to add the fan roof flange onto the adapter with butyl seal tape (if I can get a break in the Seattle rain) but I'm trying to figure out if I can use the screws that came with the fan since they look like they'd go through the adapter into the sheet metal. Do I screw into the sheet metal (I'm inclined not to)? Do I need shorter screws? I'm wondering what opinions are out there.

For the curious, I'm mostly following the Moreys in Transit (http://moreysintransit.com/install-roof-fan-van/) approach with the only difference being that I didn't believe that I could make the jig saw cuts from the top of the van on a ladder (arms to short or something) and from the inside the jig saw hangs up on the ribs so I cut the square out with an angle grinder.

 

[Tom Schwartz]

I mostly followed Morey's install too but regarding the screws, I went with Annie's build advice and used machine screws that went through the van roof and then through a wood picture frame that I made to add rigidity to the install. I'm very happy with the way it turned out.

 

[Hein]

It's fine to let the screws go into the metal. Helps to drill a pilot hole first. If a screw will hit the roof support beams (ribs) then you'll want to drill a clearance hole in that (from inside) so the screw doesn't engage it and pull the skin down in that area.


The steps :
1. apply butyl tape on vent fan flange.
2. place vent/flange on adapter
3. drill pilot holes and clearance holes (from inside) if needed.
4. install screws but only snug so you don't compress and squeeze out the butyl tape.
5. coat vent flange, screws, side of adapter and onto roof with sealant. (we used Flexseal in grey)

 

[surly Bill]

structurally, going all the way through the metal into a support on the other side would be optimum. With glue AND screws you don't have to worry about separation.

 

[radley]

It's fine to let the screws go into the metal. Helps to drill a pilot hole first. If a screw will hit the roof support beams (ribs) then you'll want to drill a clearance hole in that (from inside) so the screw doesn't engage it and pull the skin down in that area.


The steps :
1. apply butyl tape on vent fan flange.
2. place vent/flange on adapter
3. drill pilot holes and clearance holes (from inside) if needed.
4. install screws but only snug so you don't compress and squeeze out the butyl tape.
5. coat vent flange, screws, side of adapter and onto roof with sealant. (we used Flexseal in grey)

I was racing the rain here so I ended up using the shorter screws and not going through the metal. How likely am I to 1) lose the fan on the road, or 2) need to remove the roof tape I used to cover the screws and re-screw through the metal with longer screws? The way it is now seems solid but I'm not speaking from a lot of experience.

 

[bicyclist]

For what it's worth, I glued the adapter to the roof with 3M 5200 after drilling pilot holes for the flange in the adapter, applied butyl tape to the flange and stuck it to the adapter and screwed it down with short screws that didn't penetrate the sheet metal. Then sealed with Dicor. Haven't lost the fan and am not worried about it.

 

[morey]

My fan is still there. Even hit some tree branches the other day. I don't have screws going through the metal roof.

 

[Deadwood]

I did my roof vent before Hein came out with the adapter to make it easier. Mine is held down with a combination of VHB tape and 3m 5200. 18K miles and still holding good. I don't think it's going anywhere.

 

[radley]

Thanks for the perspectives. I think I'm going to put it in the "wait until it breaks to fix it" category. The install as seen a bunch of rain over the last day or so and appears to be leak free.

 

[magunha]

Would you put screws through the roof if mounted in the front panel? (thanks for your website!)

 

[Hein]

Our best practice recommendation is that the 4 corner screws penetrate the roof sheet metal.

All the best,
Hein
DIYvan

 

[Travlin]

I used 4 screws to hold the fan in good East-West horizontal alignment over the bow in the roof.

Butyl tape was used in layers between the fan and the roof. More for leveling than for a seal.

Eternabond Tape was then installed as the seal over the screws/empty screw holes, butyl, and onto the roof.
The fan is solidly mounted and I likely could have achieved the same without the screws.

 

[EL34xyz]

I cut my fan hole making sure to miss the ceiling ribs enough to add a frame inside
I added a wood frame on the inside
The outside screws go into the wood frame
You need something solid to secure the whole rig
Just going into wimpy sheet metal is no good, IMO

Also, the inside trim piece needs to screw into something, so the wooden frame solves that also

 

[H-Bone]

Does anyone have a link to the roof adapter?

 

[Boondox]

I'm getting ready to do my fan install this week. I got the reinforcing strips along with Hein's adapter. How do folks usually apply them? I was thinking two pieces rib to rib and two smaller pieces in-between? Anyone with pics?

 

[1x1_Speed_Craig]

Apparently, it's "that time"...I'm also a week or two from installing our Maxxfan using Hein's adapter (thanks!) and rear support strips. I'm installing mine in the rear of my 148" WB MR in the 14" gap between roof supports. Even though I own 3 grinders, a Sawzall, and a saber saw, I decided to buy a sheet metal nibbler to keep the cut & surrounding area clean. Yay...new tool.

It's fine to let the screws go into the metal. Helps to drill a pilot hole first. If a screw will hit the roof support beams (ribs) then you'll want to drill a clearance hole in that (from inside) so the screw doesn't engage it and pull the skin down in that area.

The steps :
1. apply butyl tape on vent fan flange.
2. place vent/flange on adapter
3. drill pilot holes and clearance holes (from inside) if needed.
4. install screws but only snug so you don't compress and squeeze out the butyl tape.
5. coat vent flange, screws, side of adapter and onto roof with sealant. (we used Flexseal in grey)

Thanks, Hein. Regarding the roof sealant (#5), I'm seeing a lot of size options available, from 10.3-oz. (Dicor) to 16-oz. to 32-oz. and up (Flexseal). How much is actually needed to seal up a single fan install?

Does anyone have a link to the roof adapter?

You'll find the eBay store link on diyvan.com, or the direct link here for MR/HR adapter & accessories.

 

[EnviroProf]

Even though I own 3 grinders, a Sawzall, and a saber saw, I decided to buy a sheet metal nibbler to keep the cut & surrounding area clean. Yay...new tool.

Could you please describe what a nibbler is or provide a link. That's a new one for me.

 

[Michael Ophus]

I have had one for about 35 years, It might take awhile to do a roof vent.

Keyway Nibbler Punch | Greenlee

Find product features and specification information for the Greenlee Keyway Nibbler Punch. Save time with this special application punching tool today. Shop now!

www.greenlee.com

I believe the make electric ones too.

 

[1x1_Speed_Craig]

Thanks, Hein. Regarding the roof sealant (#5), I'm seeing a lot of size options available, from 10.3-oz. (Dicor) to 16-oz. to 32-oz. and up (Flexseal). How much is actually needed to seal up a single fan install?

For future reference, and people finding this thread through a search...

Thanks for the phone discussion, Hein. He mentioned that a 16-ounce container would be more than enough to seal up the fan after install.

Apparently, it's "that time"...I'm also a week or two from installing our Maxxfan using Hein's adapter (thanks!) and rear support strips. I'm installing mine in the rear of my 148" WB MR in the 14" gap between roof supports. Even though I own 3 grinders, a Sawzall, and a saber saw, I decided to buy a sheet metal nibbler to keep the cut & surrounding area clean. Yay...new tool.

Could you please describe what a nibbler is or provide a link. That's a new one for me.

"Electric shears" may have been a little better description. Given the limited use, I ordered this inexpensive Harbor Freight tool, which is rated pretty decently.

14 gauge 4 Amp Heavy Duty Metal Shears

 

[H-Bone]

I cut my fan hole making sure to miss the ceiling ribs enough to add a frame inside
I added a wood frame on the inside
The outside screws go into the wood frame
You need something solid to secure the whole rig
Just going into wimpy sheet metal is no good, IMO

Also, the inside trim piece needs to screw into something, so the wooden frame solves that also

Unrelated to the ceiling fan, what did you use for your ceiling? Do you have photos of your whole interior you would be willing to share?