Power washing your roof has pros/cons

Bob Dunahugh

New member
Sep 17, 2012
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I got annul about the roof not being clean on this 73 that I'm reconditioning a few months ago. So I scrub, and power washed it. Kept getting dirt out of the channel that is between the roof, and side walls. After that time we didn't get much rain. Then as more rain moved in later. The leaks started to appear. I didn't associate the two till last week. So I caulked the area from the back of the door to the front. The leak above the door stopped. Then this morning after a night of rain. I found more small leaks. So it seems that I just rearranged some of the water contaminated dirt. So I think that it's best to do more power washing that seam. Get as much of that remaining wet dirt out. Thus reducing the future water/dirt from corroding the aluminum roof. Plus stop the frozen water from damaging the channel. Then later in the week. Calk that seam to stop further water intrusion in that channel. YES. Power washing caused me a problem. But will stop future damage. Bob Dunahugh
 
Frost heave is a real problem in your area. Heat/cool cycles also. Leak
checks are a constant activity. Here in Oregon, we have moss that grows on
the seams, trapping moisture. Always something.
Jim Hupy

> I got annul about the roof not being clean on this 73 that I'm
> reconditioning a few months ago. So I scrub, and power washed it. Kept
> getting dirt out of the channel that is between the roof, and side walls.
> After that time we didn't get much rain. Then as more rain moved in later.
> The leaks started to appear. I didn't associate the two till last week. So
> I caulked the area from the back of the door to the front. The leak above
> the door stopped. Then this morning after a night of rain. I found more
> small leaks. So it seems that I just rearranged some of the water
> contaminated dirt. So I think that it's best to do more power washing that
> seam. Get as much of that remaining wet dirt out. Thus reducing the future
> water/dirt from corroding the aluminum roof. Plus stop the frozen water
> from damaging the channel. Then later in the week. Calk that seam to stop
> further water intrusion in that channel. YES. Power washing caused me a
> problem. But will stop future damage. Bob Dunahugh
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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Bob, have you tried pressurizing the inside of the coach and using soap
bubbles to detect where the water is getting in at?

You can use a leaf blower, seal up the blower to one of the toll windows.

> Frost heave is a real problem in your area. Heat/cool cycles also. Leak
> checks are a constant activity. Here in Oregon, we have moss that grows on
> the seams, trapping moisture. Always something.
> Jim Hupy
>

>
> > I got annul about the roof not being clean on this 73 that I'm
> > reconditioning a few months ago. So I scrub, and power washed it. Kept
> > getting dirt out of the channel that is between the roof, and side
> walls.
> > After that time we didn't get much rain. Then as more rain moved in
> later.
> > The leaks started to appear. I didn't associate the two till last week.
> So
> > I caulked the area from the back of the door to the front. The leak above
> > the door stopped. Then this morning after a night of rain. I found more
> > small leaks. So it seems that I just rearranged some of the water
> > contaminated dirt. So I think that it's best to do more power washing
> that
> > seam. Get as much of that remaining wet dirt out. Thus reducing the
> future
> > water/dirt from corroding the aluminum roof. Plus stop the frozen water
> > from damaging the channel. Then later in the week. Calk that seam to stop
> > further water intrusion in that channel. YES. Power washing caused me a
> > problem. But will stop future damage. Bob Dunahugh
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
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--
Bruce Hart
1976 Palm Beach
Milliken, Co
GMC=Got More Class
 
Bruce. I've done the pressurizing the GMC bubble trick. Works great as long as you have the volume. Never thought of using a big leaf blower. I didn't do it this time. At this point. I've only caulked half of the right side. I'm going to do more power washing of what I haven't sealed. I'm thinking that there's more dirt that needs to be cleaned out in that joint. Bob Dunahugh

________________________________
From: Bob Dunahugh
Sent: Sunday, November 4, 2018 1:27 PM
To: gmclist
Subject: Power washing your roof has pros/cons

I got annul about the roof not being clean on this 73 that I'm reconditioning a few months ago. So I scrub, and power washed it. Kept getting dirt out of the channel that is between the roof, and side walls. After that time we didn't get much rain. Then as more rain moved in later. The leaks started to appear. I didn't associate the two till last week. So I caulked the area from the back of the door to the front. The leak above the door stopped. Then this morning after a night of rain. I found more small leaks. So it seems that I just rearranged some of the water contaminated dirt. So I think that it's best to do more power washing that seam. Get as much of that remaining wet dirt out. Thus reducing the future water/dirt from corroding the aluminum roof. Plus stop the frozen water from damaging the channel. Then later in the week. Calk that seam to stop further water intrusion in that channel. YES. Power washing caused me a problem. But will stop future damage. Bob Dunahugh
 
Actually a leaf blower with not really do the trick. You really need lots of volume to make it work. I build my unit out of large furnace blower and have tons of volume to pressurized to coach and check for leaks. It works well!

http://www.gmcmhphotos.com/photos/g6110-leak-check-air-blower.html

Regards,

JR Wright
78 Buskirk Stretch
Michigan

>
> Bruce. I've done the pressurizing the GMC bubble trick. Works great as long as you have the volume. Never thought of using a big leaf blower. I didn't do it this time. At this point. I've only caulked half of the right side. I'm going to do more power washing of what I haven't sealed. I'm thinking that there's more dirt that needs to be cleaned out in that joint. Bob Dunahugh
>
>
> ________________________________
> From: Bob Dunahugh
> Sent: Sunday, November 4, 2018 1:27 PM
> To: gmclist
> Subject: Power washing your roof has pros/cons
>
>
> I got annul about the roof not being clean on this 73 that I'm reconditioning a few months ago. So I scrub, and power washed it. Kept getting dirt out of the channel that is between the roof, and side walls. After that time we didn't get much rain. Then as more rain moved in later. The leaks started to appear. I didn't associate the two till last week. So I caulked the area from the back of the door to the front. The leak above the door stopped. Then this morning after a night of rain. I found more small leaks. So it seems that I just rearranged some of the water contaminated dirt. So I think that it's best to do more power washing that seam. Get as much of that remaining wet dirt out. Thus reducing the future water/dirt from corroding the aluminum roof. Plus stop the frozen water from damaging the channel. Then later in the week. Calk that seam to stop further water intrusion in that channel. YES. Power washing caused me a problem. But will stop future damage. Bob Dunahugh
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
Bob, Have you considered taking the rails off and resealing them? I realize it is a lot of work but after all the work you've put into the coach...
--
Patti & Jerry Burt Fresno, CA.
73 Gmc 26' Canyon Lands -
77 Palm Beach
Members: FMCA - GMCMI - GMCWS - 49ers
A truly happy person is one who can enjoy the scenery on a detour.
 
Jerry. There's just too much risk of breaking the screws off in removal. As I see it. I want to flush out all the dirt I can with the power washer. Let dry for a week or two. Then seal the seam. Bob Dunahugh

________________________________
From: Bob Dunahugh
Sent: Sunday, November 4, 2018 7:05 PM
To: gmclist
Subject: RE: Power washing your roof has pros/cons

Bruce. I've done the pressurizing the GMC bubble trick. Works great as long as you have the volume. Never thought of using a big leaf blower. I didn't do it this time. At this point. I've only caulked half of the right side. I'm going to do more power washing of what I haven't sealed. I'm thinking that there's more dirt that needs to be cleaned out in that joint. Bob Dunahugh

________________________________
From: Bob Dunahugh
Sent: Sunday, November 4, 2018 1:27 PM
To: gmclist
Subject: Power washing your roof has pros/cons

I got annul about the roof not being clean on this 73 that I'm reconditioning a few months ago. So I scrub, and power washed it. Kept getting dirt out of the channel that is between the roof, and side walls. After that time we didn't get much rain. Then as more rain moved in later. The leaks started to appear. I didn't associate the two till last week. So I caulked the area from the back of the door to the front. The leak above the door stopped. Then this morning after a night of rain. I found more small leaks. So it seems that I just rearranged some of the water contaminated dirt. So I think that it's best to do more power washing that seam. Get as much of that remaining wet dirt out. Thus reducing the future water/dirt from corroding the aluminum roof. Plus stop the frozen water from damaging the channel. Then later in the week. Calk that seam to stop further water intrusion in that channel. YES. Power washing caused me a problem. But will stop future damage. Bob Dunahugh
 
Bob, good decision I believe.
On my 78 Royale, SOME JACKASS previous owner used a BONDO LIKE
material on all the roof seams. They didn't smooth it out nor did they
completely fill the seams. Of course it cracked, of course it leaked. So,
bit by bit, I have ground off that miserable crap, and replaced it with
5200 3M flexible sealant and Captain Tully's wicking wonder stuff. Sure
wish I had access to his knuckles. I would break them one after another.
With a smile on my face.
Jim Hupy
Salem, Or

> Jerry. There's just too much risk of breaking the screws off in removal.
> As I see it. I want to flush out all the dirt I can with the power washer.
> Let dry for a week or two. Then seal the seam. Bob Dunahugh
>
>
> ________________________________
> From: Bob Dunahugh
> Sent: Sunday, November 4, 2018 7:05 PM
> To: gmclist
> Subject: RE: Power washing your roof has pros/cons
>
>
> Bruce. I've done the pressurizing the GMC bubble trick. Works great as
> long as you have the volume. Never thought of using a big leaf blower. I
> didn't do it this time. At this point. I've only caulked half of the right
> side. I'm going to do more power washing of what I haven't sealed. I'm
> thinking that there's more dirt that needs to be cleaned out in that
> joint. Bob Dunahugh
>
>
> ________________________________
> From: Bob Dunahugh
> Sent: Sunday, November 4, 2018 1:27 PM
> To: gmclist
> Subject: Power washing your roof has pros/cons
>
>
> I got annul about the roof not being clean on this 73 that I'm
> reconditioning a few months ago. So I scrub, and power washed it. Kept
> getting dirt out of the channel that is between the roof, and side walls.
> After that time we didn't get much rain. Then as more rain moved in later.
> The leaks started to appear. I didn't associate the two till last week. So
> I caulked the area from the back of the door to the front. The leak above
> the door stopped. Then this morning after a night of rain. I found more
> small leaks. So it seems that I just rearranged some of the water
> contaminated dirt. So I think that it's best to do more power washing that
> seam. Get as much of that remaining wet dirt out. Thus reducing the future
> water/dirt from corroding the aluminum roof. Plus stop the frozen water
> from damaging the channel. Then later in the week. Calk that seam to stop
> further water intrusion in that channel. YES. Power washing caused me a
> problem. But will stop future damage. Bob Dunahugh
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
John. I too used a furnace blower. Secured it to the drivers window. Bob Dunahugh

________________________________
From: Bob Dunahugh
Sent: Monday, November 5, 2018 12:33 AM
To: gmclist
Subject: RE: Power washing your roof has pros/cons

Jerry. There's just too much risk of breaking the screws off in removal. As I see it. I want to flush out all the dirt I can with the power washer. Let dry for a week or two. Then seal the seam. Bob Dunahugh

________________________________
From: Bob Dunahugh
Sent: Sunday, November 4, 2018 7:05 PM
To: gmclist
Subject: RE: Power washing your roof has pros/cons

Bruce. I've done the pressurizing the GMC bubble trick. Works great as long as you have the volume. Never thought of using a big leaf blower. I didn't do it this time. At this point. I've only caulked half of the right side. I'm going to do more power washing of what I haven't sealed. I'm thinking that there's more dirt that needs to be cleaned out in that joint. Bob Dunahugh

________________________________
From: Bob Dunahugh
Sent: Sunday, November 4, 2018 1:27 PM
To: gmclist
Subject: Power washing your roof has pros/cons

I got annul about the roof not being clean on this 73 that I'm reconditioning a few months ago. So I scrub, and power washed it. Kept getting dirt out of the channel that is between the roof, and side walls. After that time we didn't get much rain. Then as more rain moved in later. The leaks started to appear. I didn't associate the two till last week. So I caulked the area from the back of the door to the front. The leak above the door stopped. Then this morning after a night of rain. I found more small leaks. So it seems that I just rearranged some of the water contaminated dirt. So I think that it's best to do more power washing that seam. Get as much of that remaining wet dirt out. Thus reducing the future water/dirt from corroding the aluminum roof. Plus stop the frozen water from damaging the channel. Then later in the week. Calk that seam to stop further water intrusion in that channel. YES. Power washing caused me a problem. But will stop future damage. Bob Dunahugh
 
I would also think that removing the rain gutter extrusion and renewing the sealant between the aluminum top and sides is the proper way to seal
leaks, but the screws are definitely a concern after being in place for over 40 years. I wondered if painting the roof with a product like Flex Seal
would seal the leaks and hold up?
--
George Rudawsky
Chicago, IL
75 Palm Beach
 
George, if (Or when) some of the screws break off - and they will, simply drill another hole and use a new screw.

--johnny
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
 
I have removed some of those extrusions. Not a simple job. It bends the
heck out of the extrusions, and they are not readily available. So, next
best thing is cleaning, stripping, straightening the ones that were
removed. Most of the screw holes are damaged during the process as well.
Not saying that it cannot be done, it is just a royal pain in the butt. The
whole idea when you are finished is to have an attractive, leak free
repair. 'Rotts a ruck'.
Jim Hupy
Salem, Or

> I would also think that removing the rain gutter extrusion and renewing
> the sealant between the aluminum top and sides is the proper way to seal
> leaks, but the screws are definitely a concern after being in place for
> over 40 years. I wondered if painting the roof with a product like Flex
> Seal
> would seal the leaks and hold up?
> --
> George Rudawsky
> Chicago, IL
> 75 Palm Beach
>
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