Community Forums

noserider · 09-13-2014, 11:02 PM

I started my roof maintenance today. I'm replacing the black and grey plumbing vent covers and sealing with Dicor. I'm also going to use Eternabond on as many seams as possible. I have some questions.

1) On the roof cap seams (fiberglass roof) I have metal strips that cover all the seams with hundreds of screws. Whats is the original factory sealant under the metal strips? All of the screws are exposed with no sealant on them but I'm guessing they all sealed good when the were installed through the sealant under the metal stip. Is this Butyl Putty Tape or something else? I'm planning on covering the seams with the Eternabond tape but just want to know.

2) I have a luggage rack on the roof in the rear. Do people actually use these racks?? The screws and brackets that attach the luggage rack have what looks like Dicor on them. The brackets and screws for the luggage rack are very close to my roof seams on the back and sides and it might interfere with putting the Eternabond tape on the cap seams in theses areas. The Eternabond tape is wide enough to cover the seams and one side of the luggage rack bracket but it's not as clean of an install as I was hoping. Have not tried it yet. Was considering just covering the fiberglass cap seam with the Eternabond in that area and going back with the Dicor to cover the luggage rack screws and brackets. Suggestions?

3) The screw holes from the old plumbing plastic vent covers are almost the same as the new covers but not quite. Is there any problem just putting a healthy bead of Dicor over the old holes and making new holes using the old screws as I install them with the new cover? I dont have any idea what the base is under the fiberglass roof that I'm installing the screws in? Wood? I don't like to drill holes or in this case install new screws in an area not knowing what I might damage with the new screw holes.

RV Wizard · 09-14-2014, 02:37 AM

The metal strips should have butyl under them.
If it we me and the EternaBond tape is wide enough to cover both the seam of the rear cap and the holes from the luggage rack, I would remove the rack and use the EternaBond tape. EternaBond is Available in different widths, so you may want to get some wider to do this area.
Be sure to use butyl putty on the new plumbing vent caps and making new holes is Ok as the butyl putty, vent cap and Dicor will seal the area of any water intrusion. The substrate under the fiberglass where the plumbing vent is located will only be a plywood decking. You will not have to worry about any wiring. You may possibly catch the edge of a roof truss but again don't worry about hitting anything to cause damage. Good luck and let us know how you make out and include some photos.

noserider · 09-14-2014, 09:15 AM

[QUOTE=RV Wizard;2227693]The metal strips should have butyl under them.
If it we me and the EternaBond tape is wide enough to cover both the seam of the rear cap and the holes from the luggage rack, I would remove the rack and use the EternaBond tape. EternaBond is Available in different widths, so you may want to get some wider to do this area.
Be sure to use butyl putty on the new plumbing vent caps and making new holes is Ok as the butyl putty, vent cap and Dicor will seal the area of any water intrusion. The substrate under the fiberglass where the plumbing vent is located will only be a plywood decking. You will not have to worry about any wiring. You may possibly catch the edge of a roof truss but again don't worry about hitting anything to cause damage. Good luck and let us know how you make out and include some photos.[/QUOTE

RV Wizard

Your suggesting to remove the luggage rack permanently? If so, not a bad idea. I have no plans to carry anything on the roof.

I removed one of the plumbing vent covers. I think it was original and there was not any Butyl putty tape on the old vent. It was however covered very well with the Dicor. Would the Butyl be necessary if I put a thick bead of the Dicor in a ring around the screw holes?

The old vent covers also had removable caps with the metal clips you squeeze and insert inside the pipe to keep it on. The new ones have caps that are attached permanently to the base. I know that makes no difference but the pipes almost needed the length to be cut to allow the new ones to fit flush but they barely made it. I was dry fitting and noticed this. The supply house near me (PPL) only carried this style.

Thanks for your reply.

noserider · 09-14-2014, 10:35 AM

One more question. When I was removing and cleaning the old sealant (Dicor I think) I removed some around the pipe itself as it protrudes through the roof. I need to replace some of that sealant also as there is a small gap there and you can see inside the opening. Is Dicor the best sealant for that location as well? I want to get this right the first time before I seal everything up. Right now I'm just doing the prep work while I gather info from you pros on techniques.

Thanks

RV Wizard · 09-15-2014, 02:10 AM

I prefer to have butyl on anything that is fixed to where water intrusion is a possibility. The more layers of protection the better in case one layer fails. Self leveling lap sealant will continue to run down a vertical surface. I would probably use Pro flex on this issue with the vent pipe and make sure you do have a good air gap between pipe and vent cover.

Snomas1 · 09-15-2014, 06:43 AM

When I installed Eternabond I left the roof rack on and cut the Eternabond so it would go up to the rack post and then used dicor around the Ebond and post to get a good seal. I left the rack on, it helps me hold on to something when I climb on the roof. I used 4" Ebond over the perimeter seams. Right now I am having a new roof installed after hail damage in Colorado and having Ebond reinstalled on the perimeter seams!! It's the best material to do a long lasting seal.

noserider · 09-15-2014, 09:19 PM

Quote:

Originally Posted by RV Wizard

I prefer to have butyl on anything that is fixed to where water intrusion is a possibility. The more layers of protection the better in case one layer fails. Self leveling lap sealant will continue to run down a vertical surface. I would probably use Pro flex on this issue with the vent pipe and make sure you do have a good air gap between pipe and vent cover.

Great advice. Thanks

noserider · 09-15-2014, 09:24 PM

Quote:

Originally Posted by Snomas1

When I installed Eternabond I left the roof rack on and cut the Eternabond so it would go up to the rack post and then used dicor around the Ebond and post to get a good seal. I left the rack on, it helps me hold on to something when I climb on the roof. I used 4" Ebond over the perimeter seams. Right now I am having a new roof installed after hail damage in Colorado and having Ebond reinstalled on the perimeter seams!! It's the best material to do a long lasting seal.

After getting on and off the roof a few times I was thinking the same thing about needing the luggage rack for a hand hold. I like your idea about trimming the Ebond tape to fit around the luggage brackets. What did you use to cut the Eternabond tape? I understand it's a little tough to cut.