Expertise (advice) sought NF

[Sandbag]

Ok....It's obvious that there is alot of professional as well as life experience with the members of this board so i thought that I would throw this out.

 

A few years ago, my wife an I wanted to do our front walkway and porch is flagstone. I was a bit short on free time so I hired someone to do the job. He poured a concrete slab for the front walkway and left the surface rough as he advised me the mortar and flagstone would adhere better to the rough surface.

 

To keep a long story short, the flagstone and mortar held together nicely until the first winter came. After the winter, the flagstones (and mortar) began to break away from each other and the walkway/porch.

 

I have since chiseled all of the flagstone and mortar of the porch and I am left with the original concrete porch and the pored concrete slab. Now to my question.

 

Should I be busting out this concrete slab and starting from scratch or can I hire somebody who knows what they are doing to come and finish what we originally wanted (flagstone walk and porch). As well, should I be waiting until spring to have this done or is the weather still warm enough for this type of work.

 

I am going to try attach a couple of pictures of the mess that I have right now to try and better illustrate the problem. Hope it works.

 

Any and all opinions appreciated except for the shots at what I already realize was a bad choice in original contractors. lol

 

Cheers and Thanks

 

(Ps first shot at photos. I promise the next ones will have gills)

 

Craig

 

 

 

 

 

[solopaddler]

Okay well, if you've got improper drainage then that may be why the walkway didn't last.

Generally speaking you need about 2" of fall for every 12'.

You can check this with a transit, or the old fashioned way with a 2X4 that's as long as your walkway.

Use a 2X4 by laying it on the walkway and putting a level on top. Raise the 2X4 'till the board is level, then measure the drop.

If your drainage is inadequate, then yes you'll likely have to bust up the concrete and start from scratch. I'm not a big fan of patching an existing concrete base to fix drainage problems.

 

If your drainage is okay then the stone wasn't laid properly. You need a minimum of 1/2" of portland cement to do this job properly.

If the wrong cement was used or not enough cement was used that could've been the cause of your problems.

Assuming everything is done properly and the drainage is okay an installation like that should last forever.

 

Good luck

[Sandbag]

Solopaddler..Thanks for the response....

 

Drainage was never an issue. It was more that the material (mortar/portland or whatever he used) was not the proper material to use. The original poured slab is still in good condition and drains fine by itself. it is just unsightly and unfinished looking.

 

Cheers

 

Craig

[Gerritt]

Mortar and Concrete DO NOT like to bond together (Same as concrete to concrete).... unless a bonding agent is used... sounds to me like it wasnt... Hydraulic pressure is a PIA... I think a simple bonding agent would have sufficed here... Cheap product too..

 

Gerritt.

Edited October 28, 2007 by Gerritt

[Sandbag]

Thx Gerritt

 

Since i am back to square one then with a clear porch and clean slab, would it be your opinion that if the proper bonding agent was used, the job could still be done with the existing slab?.

 

Obviously I am not holding anybody to a helpful opinion, just trying to sort out what i am going to do in my own mind.

 

Cheers

 

Craig

[Sinker]

Ya, sounds like the guy didn't use a bonding agent before he put the mortar down on the concrete. If not, the water will get under it, and when you get frost, it will crack and break free from the concrete.

 

Home depot sells it, its called acrlyli bond. Just brush it on with a paint brush, and your mortar will stick for good. I've used it a fair bit myself with no problems yet.

 

 

Sinker

[HTHM]

On most flagstone walks that I have installedI prefer to have a rough surface that I can place my mortar on. When mixing the mortar add a product called Abitol, it is an acrilic polymer bonding agent. Mix your mortar with .5" of slump, slop some abitol on the raw concrete and stone, slather mortar on generously and place your flagstone with the aid of a straight edge to maintain grade. After stone is placed, beat the heck out of it with a rubber mallet in order to seat the stone to the mortar base. When you have 5 - 8 joints done, use a wet sponge to seal the mortar in the joints and clean your stones.

At this time of the year, you will want to cover the work overnight with bubble cover in order to maintain a temp above freezing. Do not use the walkway for 48 - 72 hours after completion.

The stones that you have left over will need to be cleaned of the old mortar, and possibly acid washed in order to ensure a good bond when you are laying them.

If you would like the name of a good landscape contractor shoot me a PM and I will be happy to send you one. I no longer do this type of work, getting too old.

[Sandbag]

hometownhandyman...

 

Thanks for the reply...I will be using new flagstone as alot of the old stuff was broken to pieces when I removed it from the surface. Thank you for the info.

 

I will send you a PM for the lanscape contractor referal

 

Craig