roof sealants, what is current for small jobs

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roof sealants, what is current for small jobs

October 22, 2019, 02:24:35 pm

I am covering existing sealing. Tank vent stacks, area around roof vents and emergency exit (we have a 07 MB) and shower skylight. Which is easier to use, our drive way has a slight, but noticeable, incline. I recall hearing about both Decor Self Leveling and 3m 5200. Which one is preferable for this application (my gut is telling me the Decor)? Is there another product I should be looking at?

I have already done the long seams with etarnabond.

Thanks in advance,
John

Re: roof sealants, what is current for small jobs

Reply #1 – October 22, 2019, 02:38:53 pm

Hello John. I believe self-leveling Dicor is the preferred sealant for your project. And it’s what we’ll use when we re-seal the same areas.

Are you planning to remove the old sealant first? Margee and I are considering to do this project ourselves. I know it’s something we can do, but we’re just not sure about our lack of physical flexibility. That’s why it’s in the “consideration” category. 😀

Re: roof sealants, what is current for small jobs

Reply #2 – October 22, 2019, 04:24:19 pm

the sealant is in good shape in most places. But I have had leak in the bath from the fan vent, and I noticed cracking in the sealant around that vent after I took the MAX Air cover off. For now I am just going to cover the existing cracks unless the old is pulling away. I'll pay close attention to the lip where the sealant and roof meet. If the brain trust here speak up and suggest I remove the old stuff then I will.

Note; I am not being completely truthful when I say I. My brother will be helping with the job and I suspect he will be doing a bunch of the work. Because of my knees I can no longer safely navigate the top of the roof. I'll get what I can from ladders against the sides but my brother will be getting the rest.

I have watched a couple of YouTube videos and this seems to be the way to go. Below is one of the better ones. Despite appearance it is not about a TPO roof.

John

https://www.youtube.com/watch?v=iXUcBdVnhwI

Re: roof sealants, what is current for small jobs

Reply #3 – October 22, 2019, 06:01:03 pm

Give the old sealant a good scrubbing, with soap and water, next a quick wipe with acetone or lacquer, then apply Dicor, either self or non-leveling.
Self leveling is thinner and flows, non-leveling is good for vertical surfaces.
If you see cracking or where the sealant has pulled away, removal with a sharp 1" putty knife or oscillating tool with a sharp chisel blade works well for this.

Usually when a roof vent leaks, there is a crack in the fan's cover or frame, the sealant shouldn't break down between the roof and the bottom of the vent. I have never seen a Factory installed fan leak around the frame.
Has a Maxx fan(s) been installed.

Larry

Re: roof sealants, what is current for small jobs

Reply #4 – October 22, 2019, 06:21:55 pm

thanks Larry. The leak was in the bathroom, water dripping from the plastic trim that screws into the roof interior roof. We removed a Max Air vent cover/housing that allows the vent to be open on the rain. Then cleaned and put blue painters tape over the sealant around the fan and also around the skylight. That was before the rain this evening. So far the bath is dry. I’m ordering two tubes tonight from Amazon.

Re: roof sealants, what is current for small jobs

Reply #5 – October 22, 2019, 06:45:02 pm

John, I went through all of this last winter and basically it's what Larry said. I used self leveling exclusively on the roof. You can make it look nice when you are done but the non leveling is a different deal. If your doing all the roof penetrations, you are going to want more than 2 tubes. Six might get you by with maybe some left. Don't forget about the guard rail legs, they need love too.

Jon

Re: roof sealants, what is current for small jobs

Reply #6 – October 22, 2019, 06:51:32 pm

John, just a little visual.

Jon

Re: roof sealants, what is current for small jobs

Reply #7 – October 23, 2019, 08:15:11 am

I have a 2004 LD 26.5 mb. My unit was garage kept and sealant on roof was still in great shape but aging. I decided to call LD and ask what sealant was used. They are using Loctite PL S40 and that is the old name and the same sealant is PL windows,doors and siding polyurethane sealant (I found it at home depot). It has very elastic property...video shows it being stretched 10x longer. I cleaned and prepped the roof, did a final wipe with denatured alcohol. Tapped off sides 1/4 wider and applied the new sealant. Worked my way down one side at a time removing the blue tape 18 inches at a time so it did not cure to the tape. Applied 303 to all plastic covers and the roof was finished.

Re: roof sealants, what is current for small jobs

Reply #8 – October 23, 2019, 10:15:10 am

Quote from: Franram - October 23, 2019, 08:15:11 am

They are using Loctite PL S40 and that is the old name and the same sealant is PL windows,doors and siding polyurethane sealant (I found it at home depot). It has very elastic property...video shows it being stretched 10x longer. I cleaned and prepped the roof, did a final wipe with denatured alcohol. Tapped off sides 1/4 wider and applied the new sealant. Worked my way down one side at a time removing the blue tape 18 inches at a time so it did not cure to the tape. Applied 303 to all plastic covers and the roof was finished.

Just a quick question please. Did you remove the old sealant? And thank you.

Re: roof sealants, what is current for small jobs

Reply #9 – October 23, 2019, 12:06:32 pm

Hi John,
I haven't had to reseal anything on top of our Lazy Daze due to its fairly new age, no leaks yet, and the fact that it lives in the barn. I did however, do many re-seals and vent replacements on our previous two Lance campers with an aluminum roofs.
I removed all of the old Dicor lap sealant while doing a vent replacement. At ambient temperature, that stuff is really difficult to remove. I found that it is much easier to remove if you heat it with a heat gun and then remove it with a putty knife. It can be pulled off when warm by heating it, working up an edge with the putty knife, and then pulling it up with pliers. It is still hard work, but much better when nice and warm, almost hot.

I'm leery of using 5200 on anything that isn't intended to be permanent.

I have always cleaned things well with alcohol or acetone and then resealed the job with butyl tape between the vent and the roof, and Dicor lap sealant over the vent/roof junction. No leaks on any of those jobs.

Good luck.

Harold

Re: roof sealants, what is current for small jobs

Reply #10 – October 23, 2019, 01:41:12 pm

Ed and Margee,
I thought about it but after inspecting the entire roof it just seemed completely unneccessary. Because it was only outside an average of 3 months a year the sealant was still soft and sticking well. I removed a 3 inch by 1/4 inch piece that was sticking out uneven....I worked a good 5 to 7 minutes to cut through and pry up with a 5 in 1. That showed me it was not coming up easy. I spread the sealant over the old. Working it in the uneven ridges and curves making sure there was no air bubbles. I tapped off 1/4 more to the left and right of the old sealant to give it a new edge. It was not necessary to apply it thick just good coverage. Around the plastic covers I made sure to come up almost 1/2 inch on the plastic bezel for a good new thick seal.
Working around the feet of the solar panels was a trick. I shot a thick amount as far under the panels onto the old sealant and then smoothed it out with a wooden tongue depresessors (from doctors office or craft store).. I manage to smooth it out nice and even. On the escape hatch I proped it open so I could coat the frame 1/2 up for good coverage. On the hinge side, tape off the hinge to keep the sealant from getting on it. The opening here with lid closed is small. Do it after other 3 sides of hatch.
Apply a dab of sealant on all screw heads/raised area for good measure, smooth down to make better contact/adhesion.

Re: roof sealants, what is current for small jobs

Reply #11 – October 31, 2019, 10:04:05 am

An update. My brother came by and did the roof work. I did the “gofor” work on the ground. Due to time and weather he only did the roof vent, skylight and tank vents.
The existing sealant was largely in good shape from the work the factory and previous owner had done. There were two spots on the skylight over the shower where sun damage had opened up cracks. We cleaned the area to be re sealed, and lates a new bead around the fixtures paying special attention to weathered areas. We did not pull up the old sealant as it was firmly bonded to the roof.
Note. I say “we”, but my brother did all the hard work. I just pointed him on where and showed him the how (YouTube videos). In college he worked in home construction and has a nice touch for this kind of work so the RV is better off with him doing the work.
After a significant rain last night (10-30-19) the inside of the RV is dry today (the morning after the Nationals won the World Series). There is more rain in the near term forecast. We will catch the other vents and areas next week.

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