I could write a book, but I won't. The best way to do it is the way that gives you 100% bond, and is the fastest. I check bond by bouncing a tennis ball, tapping with a broom handle, whatever.:thumbsup:

 

Do you use any bonding agent?

edit...1" bluestone, 3/4" bed??? that oiesn't seem right to me. 1" should be more of a tile tyoe install

 

Portland slurry (acrylic/Portland) brushed onto the stone and then bed it with a modified type S mortar.

I do the old knuckle or trowel handle tap to check bond.

 

¾" bed? all the stone we lay HERE, has at least 2 - 4 " of a portland cement / sand bed,

My question is what is the correct mortar mixture for laying wet laid bluestone?

there is no correct, depends on what the Engineer asks for, location, etc.. HERE, we aim for 300/350 kg portland per cubic meter of mortar mix,
which is a 1 part 3 parts mix. I like using coarse sand too. And I have never buttered the backside, probably difference in the stones we use

 

¾" bed? all the stone we lay HERE, has at least 2 - 4 " of a portland cement / sand bed,

That sounds like a drypack bed.

 

I will add too that when we pour the joints, a few days after install, we use a 2 parts portland, 1 part finer sand.

 

I typically use a type S mix, maybe a little rich with the ratio. 2.5:1 instead of 3:1

 

Weld o bond the back, mortar usually type S. 1/2 bed joint, furrowed uniformly beat down with a rubber mallet.

 

Most of our bluestone is 1 5/8" thermaled, with a sawn back. We generally set them in 1/2" TO 3/4" bedding mortar, typically 1 part portland to 3-4 parts mason sand, along with just enough lime to control bleeding. Also, a little bonding agent in the mix. We also use a portland slurry, or thinset back butter, to the backs of the stone, depends on the mood.......

 

Been experimenting lately. For large bluestone projects I steer people away from wet jobs and set in compacted 1/4"stone and use polymeric in the joints.
For steps (about the only time I mud bluestone) I run the 4" grinder on the back and score some shallow kerfs in. Then set using Stone Veneer Mortar.

 

Carl

Whats the main reason you been shying people away from wet laid stone flat work?

 

I am not sure of his exact reasons, but I agree with him and here is why.

Every wet laid patio I have taken apart had a failed bond and terribly cracked joints. Most of them weren't through any fault of the installer, just age. I think once the moisture can begin to get under the stone it isn't long before all hell breaks lose.

I spent some time with a hardscaping company and it was nice to be able to see how they do things compared to how masons typically do things and I honestly think that in my part of the country dry laid brick and stone is a better way to install than wet laid, provided the base is prepped right. It can be installed to be either permeable or not depending on the location and I think because the base is dynamic it is less susceptible to frost damage, and more easily fixed if it does occur.

 

Bluestone seems to be so inconsistent and unreliable. Whether it starts peeling apart or has stains. I dunno just seems there are a lots of phone calls I get which lead to fixing or ripping apart a bluestone project

 

I can definitely relate to what you said. Not sure of all the states "bluestone comes from however,the products sold here range from a pale green blue to a extremely dark, rich gunmetal blue that is close to black.

That blue / black stone is the stuff that I feel has the best durability.Some guys say it comes from up state New York. Does anyone have thoughts / ideas regarding this ?

 

There are steps around town I labored on in 88 that still look like the day we built them.

 

I'm in a similar area as sitdown, and my typical response is that wet laid is better for the first 10 years and dry laid is better for the next 90

 

When I have to bond blue stone to horizontally to concrete or to cap a masonry wall, I use ardex-x32 and tuck point the joints with type-s. http://www.ardexamericas.com/en-us/Products/tilestone/Pages/X32.aspx This has always worked really well for me. Pressing thick stones in a setting slab works too but can get messy. Of course any of it is only as strong as the pour. This was put 16 years ago and nothing come loose. We get some foul winters here.

 

When I have to bond blue stone to horizontally to concrete or to cap a masonry wall, I use ardex-x32 and tuck point the joints with type-s. http://www.ardexamericas.com/en-us/Products/tilestone/Pages/X32.aspx

:thumbsup:


These guys make some good stuff for the same application.

http://www.laticrete.com/architects/products/surface_preparation/thick_bed_mortars_screeds.aspx

 

Like Karl, I usually score the underside of the stone with an angle grinder first. Sponge it off, set it in type S. I've really never had flagstones pop up on me.....

I try to never set them in a mortar bed any deeper than 1"

I always try and wet-lay flag stone that are no thinner than 1"--often going with inch and a half. I feel like the thicker stone is less likely to come loose, so I use thicker stone.

I let the cement harden beneath the flag before doing the joint--and do the joints with rather dry mortar, pressed firmly into the joint.

My method has worked well for me....but then I rarely do wet-lay, having an extreme preference to dry lay flagstone.

 

Whats the main reason to not use type m cement? It seems like everyone is recommending type s.

Is bluestone just difficult to work with because of its properties? We recently wet laid 3000 sq ft of 2x2' travertine patios. We used type m to 16 shoves of sand. We laid a 3/4" bed, used a notched trowel to apply thin set to the back of every stone. Out of 3000 sq ft there wasn't a single stone that made a hollow sound.

Then we lay 100 sq ft of bluestone yesterday with the same exact method. 90% of the stones have bond issues. What gives?

I did buy some type s this afternoon. I mix one bag of type s with 1 shovel of lime to 16 shoves of sand. I notices the mortar was a lot more sticky. If i picked up some in my hand it would stick to my fingers if i tried to roll it into a ball. Now with the type m it wouldn't stick to my fingers. Is my main issue just the cement i am using or??

 

I brush on weld o bond to the backs of my bluestone and use either N with a scoop of porti in it or S.

Type M is mostly portland I believe we used it for laying block down south other then that never have touched it again.

 

Type M is about as workable as maple syrup. Engineers/architects should take some masonry specific classes.

 

yep portland....mason sand = separates....

 

So I have a pallet of type M on site. Can I mix half of a bag of type m with half a bag of type n to get something close to type s?

 

Just add more sand to the type M masonry cement. That will get you a type S

 

You are talking masonry cement right?
My quick calculations say 2 shovels.
Type M is about .19 shovels per pound
Type S is about .22 shovels per pound
No lime needed

 

The m has more Portland then s and n is 50 50. I would add a quarter bag of lime and enough sand till it feels like decent mud.

 

OK guys...old thread but I really cant see a clear answer to the question as to what we should use.


if anyone can help will be great. We normally do pavers on crushed stone with sand and just awarded a 6000 sq ft job 'wet set'
with 12X18" bluestone, abut 1" thick and the finished height needs to be
matching with another section already laid down at about 3.5" finished height, so a 2.5" to 3" thick bed of...

What... portland?

Do we need a bonding agent on the back of each tile?

This is for a high traffic courtyard in a NYC public park in the pavilion type area.
We need to order materials asap. Like today or tomorrow morning.


Thanks!

 

As to bonding agent, you absolutely need something. Thinset, pure portland, weldobond will all work if you know how to use them. As far as method and mortar mix for setting, you should have known this before you bid the job. I would get someone in who does!!!

 

Yeah thats a mess. Ive done that on a pool due to the huge pitch the concrete guys put on the crete.

I regretted not re-pouring it with portland the 2" and it would have still been a 1" bed joint. Not even sure if 2" of portland is ok to do or not. I was struggling like a 17 year old trying to pop off a bra.

But yeah, set up a pasting station on saw horses, make sure you lay our your pattern on grid paper so the tenders can pre paste the backs ahead of you, otherwise, well , it will fricken suck the life out of you.

Grid paper, 1 square is 6", just lay it out, takes an hour and saves you days.

 

Your going to mix the mud stiffer and stiffer to prop up the stones and that is a mistake. Bluestone need to be set in something that has moisture.