Seal Bluestone cap

[grussell]

Hi All-
First time poster here, so please forgive any newbie mistakes in my post.
Ok, so this spring, I hired my former brother-in-law (who is a mason) to build a stone retaining wall in my front yard. He worked very hard at it, and did a great job at a great price, and I couldn't be happier.
But, one thing that I still need to do is seal up my blue stone cap. Living in Rhode Island, I'm worried about water getting into the wall and freezing. The gaps are only about 1/8"-1/4" wide or so. A manager at the local building supply suggested using type S mortar, but I don't think he knew the gaps were so narrow. My former brother in law just suggested using silicone. Do you guys have any suggestions?

Thanks in advance,
-Glenn

https://lh4.googleusercontent.com/-WhIO1olImzw/TgEETW_xLVI/AAAAAAABi0I/vX1ghJHKwBI/s1024/2011-05-25%252520TopCoat%2525208.JPG

https://lh6.googleusercontent.com/-_NEZnCo9Ozk/ThcGd2iXTXI/AAAAAAABj8c/wXljA2I4SOo/s1024/2011-06-27%252520front4.JPG

https://lh5.googleusercontent.com/-xT68qdaSyro/TgyJbpq69hI/AAAAAAABjpk/oK0JUj3IFc0/s1024/2011-06-27%252520front.JPG

[concretemasonry]

The lights really must look good at night. He certainly did a good job of cutting the caps stones to fit so well.

That type of wall is not intended to be "sealed", so it can drain excess moisture out of the soil.

I hope you used a granular backfill and put in some perforated pipe behind the wall to remove the moisture and eliminate the saturated soil from feezing and moving laterally more than normal.

Dick

[grussell]

Hi Dick-

Thanks for the reply.

Yeah, it does look pretty cool at night. I think the cooler thing isn't the low voltage wall lights, but rather the solar lights inlaid in the bluestone. You can just see one in the pic above. You can buy cheap ones at Home Depot for probably $15, but they only last 3 years or so because they have internal batteries that eventually fail. I wasn't going to cut bluestone for something that was going to last just 3 years. These are quite expensive, but they have ultra capacitors in them instead, so they're warrantied for 10 years and supposedly last longer.

I'd like the think that the wall is a combination of both his and my ideas. (The lighting was mine, and he installed it very nicely) I actually spent probably on average 2 hours a day actually working with him on it. Being an engineer, I was always concerned with every detail, and thankfully he said he actually liked the collaboration.

I did question him about not using a granular backfill and perc pipe. But, the soil there is almost pure sand and a little gravel. It drains like a sieve. And there is a drainage area at the low spot which takes any water (especially from the roof), and shoots it through the wall and onto the blacktop. Also, at most, the soil is only 18" higher than the other side of the wall, and usually less.

Back to the topic at hand... So, you're not worried about winter water going through the bluestone cap cracks, and getting down inside the wall and freezing/expanding/heaving the wall apart? You wouldn't fill the cracks with anything? (There is obviously mortar inside the wall.)

On a semi related topic... Do people ever use a liquid sealer to seal the bluestone itself (not the wall this time) to possibly bring out the color in the bluestone? I thought I'd seen that somewhere before.

Before I do that though, I gotta find an acetylene torch and give 'flaming' a try. We got the cap at a great price $12 per sq foot, but found out later a few of the pieces had one edge that was unflammed. I've got some practice pieces to try it on first.

All the best,
-Glenn
https://lh5.googleusercontent.com/-W3J-sCIOJR0/Thui2KHd4JI/AAAAAAABkZU/9PQajF-zfTw/s1024/A%252520P1000438.JPG