Advice for DIY of mastic seal around pool

edavis6678

Member
May 20, 2014
17
Southern California
So I've decided to re-do the mastic around my pool and came here for advice. (can't find a decent contractor to do the work, so I've decided to DIY). The old mastic is very old and hopefully with it being like this for the past few years hasn't done any permanent damage to the surrounding deck and coping.

Here's a shot of what it looks like - can anyone tell me what I should be looking for to see if there has been damaged caused by it not being sealed for so many years?

DSC_0076.jpg

As i investigated the many products out there to make the seal, I've decided to stick with Deck-o-Seal as a replacement (what was originally installed). The first issue i have is that the color my wife wants to use will be different from what already exists (we are getting a custom color), so the removal of the old mastic is even more crucial, especial since the old mastic was poured poorly. So as I've been cleaning out the gap I've noticed that the deck (grey cement), is about 1/8 inch higher than the Terra-cotta coping around the pool - the height slightly varies at different areas, but certainly higher up to around 1/8inch. (shown below) -- could this have been caused by settling of the cement over the years, or is this typical of pool construction?

DSC_0070.jpg

With this height difference, I'm concerned that you will be able to see the old mastic color on the edge. In addition, I'm concerned that this small height difference may lead to water collection on the seal. I've been using a scraper and tested using a drill with a wire wheel, but it's leaving marks on the concrete that don't look so good (see below) -- any advice in getting all of the old color off of the cement? Also, if the coping and deck are at 2 different heights, you have to pour to the lower of the two, correct?

DSC_0068-001.jpg

Also, regarding the removal of the old Mastic -- any advice on getting it off the Terra-Cotta? I'm currently using #2 Steel Wool along with a metal scraper which seems to be working well enough, but very hard to get it off the mortar between the bricks....I can't use the wire wheel, (will mess it up)

DSC_0074.jpg

I have more questions, but this post is getting long....basically wanted some advice on the removal and prep...it's taking me a long time just to do one side, but i want to do it correctly and have it last a long time.

Thanks in advance for reading and look forward to some comments/suggestions/tips
 

BoDarville

TFP Expert
LifeTime Supporter
Jun 5, 2012
3,844
DFW, Texas
Welcome to TFP! :wave:

While I don't have an answer for this, I'm going to bump this thread in hopes of giving it more visibility which will increase the likelihood of someone responding to it.
 

BoDarville

TFP Expert
LifeTime Supporter
Jun 5, 2012
3,844
DFW, Texas
OK, you've been waiting long enough for an answer. Did some research and found that polyurethanes and polysulfide-based products seem to be the best products to use for this application. Here's a thread that discusses this in more detail: http://www.troublefreepool.com/threads/54233-Deck-to-coping-expansion-joint-sealing. I would tape off the edges of both the coping and deck just before applying the sealant.

One thing to note...if the joint is fairly deep, use backer rod to control the depth of the joint. Backer rod is a round foam material that is placed in the joint and held at the proper depth by friction. Use a backer rod that is a bit wider than the joint. For example, if the joint is 1/2″ wide use at least a 5/8″ to 3/4″ rod.

edavis6678 said:
could this have been caused by settling of the cement over the years, or is this typical of pool construction?
Could be either. If you have noticed a change in the elevation over time, I would suspect settling.

edavis6678 said:
...regarding the removal of the old Mastic -- any advice on getting it off the Terra-Cotta? I'm currently using #2 Steel Wool along with a metal scraper which seems to be working well enough, but very hard to get it off the mortar between the bricks.
That will work. Other suggestions are a wire scouring pad and coarse grit sandpaper. Keep in mind that you don't need to get every last bit of the old mastic off. If your pic is representative of that amount that has been removed, I'd call it good. The tools you are using along with the one's I have suggested will score the sides of the Terra-cotta enough to give the mastic material a better "grip" on the surface. If you want a little extra insurance promoting good adhesion, I would wipe the surface with rubbing alcohol just to remove any oils or fine particles right before applying the sealant.

edavis6678 said:
...if the coping and deck are at 2 different heights, you have to pour to the lower of the two, correct?
Generally, yes. You could try angling it slightly from higher to lower as an extra measure to prevent water from "ponding" - try using a wallpaper scraper or similar plastic/silicon implement. Keep lots of paper towels (along with a small plastic bag) around to wipe the excess sealant off of your angling tool of choice and to dispose of the paper towels.
 

edavis6678

Member
May 20, 2014
17
Southern California
Thanks for the reply - I think my post was a bit overwhelming and load of info - i did do some more research and have settled in on Deck-o-Seal in a customer color. I've also found a teenager in the neighborhood looking for summer work so will enlist his help to remove the rest of the old stuff. I am buying some backer rod and also a primer call, "PG Primer" to help it stick to the Terra Cotta -- i didn't think to use coarse sand paper, so I"l give that a go this weekend as i begin the removal.
 

Kiss4aFrog

LifeTime Supporter
TFP Guide
May 22, 2013
2,723
Hudson, WI
Pictures of your progress and the final result would be much appreciated. I have a few gaps that should be filled in too.
 

edavis6678

Member
May 20, 2014
17
Southern California
update...I have a week off from work...a little stay-vacation and some relaxing work around the pool...My original pictures were taken of just 1, 15ft side of the pool...The full removal of seal began today..

Below is the old backer rod and seal to be removed...

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I used a wide assortment of tools to remove...



Found that the carpenter's knife worked really well, along with the stiff scraper..the drill with the wire wheel was no good...eventually though, about halfway through, I broke down and went out and finally bought a 4 1/2 grinder...made the job a heck of a lot easier....

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After day of labor I got the majority of the old seal out...



Since the new mastic is of a slightly different color, I'm trying get as much of the old stuff off the Terra-cotta



Tomorrow I'm going to do a bit more detailed work to get as much of the old off from the mortar...

I'm a bit nervous about the actually pour of the Deck-O-Seal, so not sure what day I'm going to start that....
 

gwegan

TFP Expert
Apr 19, 2013
2,769
Sacramento, CA
If your pool was built in 1963 and you only have that minor difference between the coping and the deck you are doing great.

Keep up with the pictures!!!
 

edavis6678

Member
May 20, 2014
17
Southern California
Hi DSK -- I have NOT yet finished this - the temperature has been too hot for me to apply the material (they recommend not being over 77 degrees) --- i had some help to do project when it was a tad cooler early in the morning, but then they had to cancel. Side-tracked on work and other things; this is back on the agenda, hopefully very soon. I'll post pics once done. if you've already done your project, please post some pics/advice.
 

epro05

Bronze Supporter
Jun 5, 2014
276
Keller, Texas
I replaced my Deck O Seal this year. Here's some suggestions.

1. Get some of this masking tape. It sticks well to deck/coping, and helps prevent the Deck O Seal from getting on surfaces that you don't want it to get on. I taped the deck side and the coping side. I think I found it at Home Depot. Do not leave the tape on more than 2 or 3 days though, or it will be difficult to remove.

2. Do not apply above 77 degrees. I found the working life of Deck O Seal to be less than 1 hour. It gets too thick to squeeze from the bottle after that. I bought a ketchup squeeze bottle from Walmart so my wife could be dispensing Deck O Seal along with me (Cut the plastic tip off to get a proper size hole for dispensing).

3. Look at this video. It has some good tips.

4. Don't push the backer rod too far down or you will use lots of Deck O Seal. The instructions should tell you the height/width ratio of the seal.

Hope this helps.
 

edavis6678

Member
May 20, 2014
17
Southern California
Thanks for the tips...

I replaced my Deck O Seal this year. Here's some suggestions.

Do not leave the tape on more than 2 or 3 days though, or it will be difficult to remove.
yep, i made 1 big mistake -- had some people over at the pool before I could finish the pour and wife insisted I tape the open gap up for the party so no one would trip on it, nor excess water get in....well, long story short, i taped it up, but didn't remove tape for like a week; it's been a nightmare getting it off in places -- certainly delayed things, plus the heat here has been rough to do any work past 11am.
 

edavis6678

Member
May 20, 2014
17
Southern California
The never ending project is hopefully going to be complete tomorrow -- hopefully without too much heartache. Finally the stars align: cool weather + day off + father-in-law available = time to finish

The pour is early tomorrow while the weather still cool.

Today installed the backer-rod...used sand to fill the gap and normalize the height so the backer rod was 1/2 inch deep to the 1/2 width...it's not 100percent 1/2 by 1/2, in some places it's deeper, but i figured I have plenty of product, best to have deeper gap than too shallow.

any last minute advice?

The Backer-Rod



Installed



More exciting pictures!



Are you getting as excited as I am? :)

 

swoopman

Well-known member
Jul 26, 2014
213
Annapolis, MD
I don't have any advice for you but I am excited to see the progress and am looking forward to updates. This same project is in my future so I am interested to see how it all works out for you.
 

edavis6678

Member
May 20, 2014
17
Southern California
Well, I finally got this project done -- yes it took me almost a year, but between very hot weather, getting some extra help, and taking the right day off it's finally complete.



Some additional words of advice:

1) Finish it in 1 day -- i started too late in the day on the first round and had to stop halfway because of it getting too hot. I only had 1 day off to complete so I had to wait for another couples months before I could actually finish
2) Back fill with more sand underneath so you aren't using so much material on top.
3) Although it's not suggested by the manufacture, sprinkling of sand on the top makes it look really nice.
4) Don't be afraid to get a customer color -- i think it made it look better.
5) When mixing; go slow - if you mix too fast it creates bubbles (see pics below)
6) Don't beat yourself up if it isn't perfect -- just realize you saved yourself a lot of money doing it yourself
7) Next time i do it, i may consider hiring someone to just to assist on the "pour"



--------------other pics----------------



(notice the bubbling) - don't mix too fast!



(don't use Duct Tape!!!)



be very careful with PG Primer -- i spilled some and i now have a permanent stain - i don't think I'll be using this next time.
 

Steve S

Member
May 11, 2012
14
Congrats..That looks like what I think mine should look like, but doesn't--especially for freeze thaw climate..My office of consumer protection say this is industry standard..it is 7 weeks old.It is deck o seal.

deck 0 seal - Album on Imgur

I have looked around but can't seem to find any reference to the height of the DOS in relation to the sides it goes between, in my case Cambridge pool coping and pavers..Is it just common sense to get it as high as possible but not higher than the adjacent surfaces. 75% of mine is more than 1/8" low and some as much as 1/4"
 

PoolNovce

Active member
Jul 22, 2016
28
San Francisco
I don't have any photos to show yet but what about any gaps between the pool and the surrounding ground? I realize the backer rod holds up some of the seal to be put in but in my case I have a void that needs to be filled where any backer rod would go. I am thinking of using play sand? Is that a good idea?