Roof coating before or after?

[McDave]

I am going to coat the roof of my 6x12 with Henry's reflective roof paint, but I need to cut in openings for the shower vent/fan/light, and a black tank vent. I have removed the original crank-up vent in the center as that is where the A/C will be installed. Should I paint it now while the roof is clear and it would be easy, or wait till everything is installed and use the paint as a additional sealer over the lap sealant?

Thanks in advance for your responses.

McDave

[Jrst67]

Painting first will make sure all areas of the roof are coated as the paint is designed to do. Painting later is asking paint to become a secondary sealer. In the end, you won't see it and ultimately its your preference. I say let paint be paint and let sealant be sealant. Just my novice opinion.

[absolutsnwbrdr]

I'd cut the openings and then paint. That way you are sure you aren't scratching a freshly painted roof with your tools. Then install your items with sealant.

[hankaye]

McDave, Howdy;

Sealant needs a well cleaned surface to adhere to, the strength of the bond depends
upon what the sealant is bonding to. Same for the paint ... If I was doing what you will
be doing I'd clean the roof, cut the holes, mount the items apply the sealant and allow
it to fully cure then paint. I would not try to paint the sealant.

hank

[McDave]

OK, all intelligent responses. So here is my new plan.
1.Clean roof
2. Locate and cut in holes for vents
3. Mask off areas around vents where sealant needs to adhere to metal
4. Paint roof while still free of obstructions
5. Remove masking, install vents w/Dicor tape, apply lap sealant

Since roof had no leaks before, the Henry's is really only to reflect sunlight to help reduce temps, not to seal leaks. Application with a roller will be easier if roof is free of obstructions, and freshly cleaned/prepped areas around vents should assure good sealing surfaces.
Thanks for the responses and food for thought. Build journal and pics coming soon...

McDave

[roadinspector]

FYI: I have not used Dicor before but can speak from experience that Eternabond tape is an award winner in my book. I have roof repairs and sealed around all my roof vents with absolutely no problems for several years.

[McDave]

I misspoke when I said Dicor tape, that was just generic term. The actual name is "Tacky Tape" 3/4"x1/8" butyl tape. The lap sealant is Dicor self leveling lap sealant. This is for a metal roof, the butyl is a putty type affair that goes between the outer roof and the vent, then the vent is screwed down, then the seam and screws are covered with lap sealant. The Eternabond tape you speak of seems to do the same job as the lap sealant. Looks like it could be handy to have around. I just went with the lap sealant as that was what the manufacture used on the seams and the original vent. Plus the black tank vent is round and it may be easier to use the "liquid" than tape with straight edges. My first attempt at this so we'll learn something, but yes if I am doing it wrong, PLEASE stop me before I make a mess!
Thanks for the input.
McDave

[roadinspector]

I misspoke when I said Dicor tape, that was just generic term. The actual name is "Tacky Tape" 3/4"x1/8" butyl tape. The lap sealant is Dicor self leveling lap sealant. This is for a metal roof, the butyl is a putty type affair that goes between the outer roof and the vent, then the vent is screwed down, then the seam and screws are covered with lap sealant. The Eternabond tape you speak of seems to do the same job as the lap sealant. Looks like it could be handy to have around. I just went with the lap sealant as that was what the manufacture used on the seams and the original vent. Plus the black tank vent is round and it may be easier to use the "liquid" than tape with straight edges. My first attempt at this so we'll learn something, but yes if I am doing it wrong, PLEASE stop me before I make a mess!
Thanks for the input.
McDave

Opinions are like a holes, everybody has one. Somefolks will fuss about butyl tape, I personally used it. When I pulled my windows & stuff from my donor old trailer, the butyl tape was in excellent condition. When I redid my roof vent, I used butyl between the vent and the metal roof. I cleaned all excess that squeezed out then added eternabond around the seam for good measure. I'm seriously allergic to roof leaks.
Enjoy your build!

[hankaye]

McDave, Howdy;

I misspoke when I said Dicor tape, that was just generic term. The actual name is "Tacky Tape" 3/4"x1/8" butyl tape. The lap sealant is Dicor self leveling lap sealant. This is for a metal roof, the butyl is a putty type affair that goes between the outer roof and the vent, then the vent is screwed down, then the seam and screws are covered with lap sealant. The Eternabond tape you speak of seems to do the same job as the lap sealant. Looks like it could be handy to have around. I just went with the lap sealant as that was what the manufacture used on the seams and the original vent. Plus the black tank vent is round and it may be easier to use the "liquid" than tape with straight edges. My first attempt at this so we'll learn something, but yes if I am doing it wrong, PLEASE stop me before I make a mess!
Thanks for the input.
McDave

The butyl tape is outstanding for your needs... quick tip ... toss it in the freezer
for a 1/2 hour before you go to use it, easier to handle and plays nicer especially
when it gets warm outside. Most Mobile home and RV trailer windows are seated
using the butyl tape and nothing else. My currant "home" a 5th wheel RV has all
of it's windows done with butyl tape. Dicor's self leveling is used on the roof fixtures,
over top of the butyl tape, but be careful if you have a curve to the roof the Dicor
truly does seek "LEVEL"... you may need to create a 'dam' of sorts to keep it where
you want it.

hank

[Tomterrific]

Your roof is wood? Coat the roof first. Any caulk or sealant will seal nicer to paint or the roof coating than bare wood. Also the plan of taping off areas where the metal flanges are placed has a problem of a dividing line between the coating and the sealant/caulk. A better seal is made with an overlap rather than a butt joint, do roof coating then place flange with caulk.

I used a non hardening rope caulk to set all my vents, hinges and windows. The brand is Mortite but there are others. I love this old time stuff! It is easy to work with and seals well. Anything can be removed with ease if it needs redone. i even used this caulk wrapped around each exterior screw to keep water from migrating down the threads. Did i say i love this stuff?

[McDave]

Hey Hank,
Good to hear from you again. We're just getting warmed up in Montana, but its time to get movin'. It'll be 110 in the shade soon. But ya gotta love those 4 days of spring. Thanks for the advice. I actually watched a youtube on installing vents and he did it just like you suggested. Thanks again.

McDave


Hey Tomterrific,
My roof is metal, I'd guess galvanized. 3 or 4 pieces seamed across. It is bare metal. The seams and vent were all sealed with dicor, and the vent had putty (butyl?) between vent and roof. I wasn't planning a butt joint, just to have some fresh bare metal for the dicor to grip to. I'll be sure to overlap the paint with dicor. Thanks for the heads up. I'm gonna look into that Mortite rope caulk. Sounds like it could solve a lot of problems. Thanks again.

McDave

[hankaye]

McDave, Howdy;

Contact yor trailer's manufacturer to see if the roof has a galvanized coating.
If so, then do a search for how to go about properly preparing it before you paint.
Lots of sights but I'd stick with a company that makes the paint you intend to use.
A quick email to their Customer Service folks might just save you time and trouble
a year or 2 on down the road.

hank

PS. Did a bit of lookin' around and found this from Henry's;
http://us.henry.com/fileadmin/pdf/curre ... chdata.pdf
Not sure of the size of your CT but from what they say 1.5 gal/ 100sq.ft.
of surface.
Also, this; http://us.henry.com/fileadmin/pdf/liter ... re_web.pdf

hank

[McDave]

Hey Hank,
OK, I was a little shook up after reading the links and researching galvanized/painting, but I think we're gonna be alright. The product I bought is Henry 587 Dura-Bright. While my roof is not new, it is in excellent condition. There does seem to be a light amount of "white rust" but nothing too serious that cant be removed with scotch brite and a light acid (vinegar) I think we'll be ok to paint directly over without the emulsion primer.

This is the Henry 587 PDF http://www.homedepot.com/catalog/pdfIma ... 6f07f7.pdf

Trailer is 6x12 Pace. Roof area should be 72 sq ft. There are 2 pictures of the roof in my gallery, I have forgotten how to post pics, so I'll relearn and try to post tomorrow.

Thanks for the heads up.
McDave

[hankaye]

McDave, Howdy;

Yep, agree, proper prep will get ya a good paint job.
Have fun, stay safe.

hank

[Gettin Started]

I just put the first coat of Henry 587 on my 6x12 v nose (total length) 14 feet. One gallon seems to be plenty coverage for my trailer which is consistent with the label that claims 100 sq ft coverage with 2 coats. The coating is thick, but I didn't get smooth coverage on the first coat, possibly because the roller i used had more nap than needed for a smooth roof...or i didn't use enough coating...or i suck at paining. My climate is dry so by the time i finished the first coat i tested adding a second coat to a dry area and it looks like the second coat will leave full coverage i.e. pure white finish.

P.S. When looking for Henry's on hardware web sites I couldn't find the 1 gallon size. But my Home Depot had it. So if in doubt, visit your local hardware store and look for in in the roofing section (not paint section).

Edit: 2nd coat achieved much more coverage although i have enough left over for a 3rd coat. I didn't use enough on the roller for the first coat.