Mortar for laying patio - - full bed or circle and spot?

Patio flagstones (slabs), concrete flags, stone flags including yorkstone and imported flagstones.
martibab
Posts: 7
Joined: Mon Apr 29, 2013 12:21 pm
Location: birmingham

Post: # 89487Post martibab

Hello all
I am a newbie here but I don't think this has been asked before. I am getting conflicting advice on what kind of bed to lay patio slabs on. Most layers are telling me that only a full bed will do. One layer who seems reputable and successful says that he now lays each slab on a circle of mortar with a spot in the middle and presses down onto this. He says that in several years he has had no call-backs using this method, whereas he had several call-backs when he used to lay slabs on a full bed of mortar. He says that his method is more work, but appears more effective for various reasons that I can elaborate if anyone’s interested.
Any helpful comments on this would be much appreciated!

Regards
Brian
Brian

r896neo
Posts: 521
Joined: Wed Feb 22, 2012 9:38 pm

Post: # 89488Post r896neo

This is nonsense and he clearly had a very poor technique if he had problems laying on a full bed.

I'd be interested to hear these reasons why its more effective.

Voids of any kind or size under paving will always create more problems than a solid bed.

Westminster Stone
Posts: 7
Joined: Mon Apr 29, 2013 3:21 pm
Location: Based in Shropshire / North Wales border - Operate Nationwide

Post: # 89489Post Westminster Stone

Laying onto a spot bed can cause moisture to come up through the slab where the base ins't, and cause black spots or patches in natural stone products, especially fossil mint which is quite pourus
Premium Paving Manufacturers, Natural Stone Suppliers and National Trust Paving Licensed Manufacturers

[URL=http://www.nationaltrustpaving.com]
[URL=http://www.westminsterstone.com]

Digital Brochure - [URL=http://www.westminsterstoneonline.co.uk/brochure.html

Bob_A
Posts: 861
Joined: Wed Feb 27, 2008 9:30 pm
Location: SE London/ NW Kent

Post: # 89490Post Bob_A

Spot bedding is bad read here
http://www.pavingexpert.com/layflag1.htm#spot

local patios and driveway
Posts: 1568
Joined: Mon May 10, 2010 9:58 pm
Location: Gatwick
Contact:

Post: # 89491Post local patios and driveway

do NOT listen to that guy. he is successful as he is cheaper because he is bodging his work, but because he is cheaper he is getting the lions share of the work locally. i dont for a second believe his pointing is standing the test of time, the reason he probably dont like a full bed is that he laid them badly and had a few rocking slabs. amateur mistake.

lutonlagerlout
Site Admin
Posts: 15184
Joined: Fri Aug 04, 2006 12:20 am
Location: bedfordshire

Post: # 89494Post lutonlagerlout

berkshire hunt
LLL
"what,you want paying today??"

YOUR TEXT GOES HERE

local patios and driveway
Posts: 1568
Joined: Mon May 10, 2010 9:58 pm
Location: Gatwick
Contact:

Post: # 89495Post local patios and driveway

forgot to ask, i would love to know the reasons he gave

GB_Groundworks
Site Admin
Posts: 4420
Joined: Sat Aug 09, 2008 3:55 pm
Location: high peak
Contact:

Post: # 89522Post GB_Groundworks

I'd love to know the bollocks behind how having a non full bed is better than having the entire flag bedded down and in contact.

Not to mention it's not British standard so he is shafted if ever hes called upon to qualify his work in court say

Does he ride a horse?
Giles

Groundworks and Equestrian specialists, prestige new builds and sports pitches. High Peak, Cheshire, South Yorkshire area.

http://www.gbgroundworks.com

martibab
Posts: 7
Joined: Mon Apr 29, 2013 12:21 pm
Location: birmingham

Post: # 89684Post martibab

Sorry I’ve only just got around to this. No discourtesy intended.
Thanks for all the very helpful comments, which were mostly - no, entirely - critical of the 'circle and a dab' method proposed by one tradesman. Someone asked what his reasons were for his method. Here they are:
1. He says he had some call backs when he laid a full bed;
2. He’s been called in to deal with someone else’s customer whose slabs on a full bed weren’t adhering well (he was able to lift the edge slabs off);
3. He’s not had a call back in the several years since he’s been doing it by the ‘circle and spot’ method;
4. He says that slabs adhere better with his method than on a full bed;
5. He says that pressing the slabs down when he levels them fills the voids underneath.
Is that all nonsense, or does he have some points?
Thanks again.
Brian
Brian

bodgeitandscarper
Posts: 345
Joined: Tue Aug 07, 2007 9:23 pm
Location: Hereford

Post: # 89687Post bodgeitandscarper

Oh Brian!
Its all bollocks!
Maintenance Man

London Stone Paving
Posts: 2199
Joined: Mon May 10, 2010 1:07 pm
Location: Surrey
Contact:

Post: # 89693Post London Stone Paving

Maybe this guys a friend of the sherrif :;):

lutonlagerlout
Site Admin
Posts: 15184
Joined: Fri Aug 04, 2006 12:20 am
Location: bedfordshire

Post: # 89701Post lutonlagerlout

he is talking rubbish
LLL
"what,you want paying today??"

YOUR TEXT GOES HERE

ringi
Posts: 125
Joined: Tue Jun 07, 2011 10:32 am
Location: Stockport, UK

Post: # 89758Post ringi

One thought….

How big does the spot in the circle have to be before it becomes a full bed when the slab is pressed down?

If the circle and spot are big enough if this much different from making ridges in a full bed?

lutonlagerlout
Site Admin
Posts: 15184
Joined: Fri Aug 04, 2006 12:20 am
Location: bedfordshire

Post: # 89760Post lutonlagerlout

When I lay a flag or slab I get the full bed to the correct level and then furrow it,as the flag as then tapped down to finished height this ensues a full bed
What he is suggesting is total bolocks
LLL
"what,you want paying today??"

YOUR TEXT GOES HERE

Carberry
Posts: 1366
Joined: Fri Apr 15, 2011 9:05 pm
Location: Edinburgh

Post: # 89762Post Carberry

martibab wrote:Sorry I’ve only just got around to this. No discourtesy intended.
Thanks for all the very helpful comments, which were mostly - no, entirely - critical of the 'circle and a dab' method proposed by one tradesman. Someone asked what his reasons were for his method. Here they are:
1. He says he had some call backs when he laid a full bed;
2. He’s been called in to deal with someone else’s customer whose slabs on a full bed weren’t adhering well (he was able to lift the edge slabs off);
3. He’s not had a call back in the several years since he’s been doing it by the ‘circle and spot’ method;
4. He says that slabs adhere better with his method than on a full bed;
5. He says that pressing the slabs down when he levels them fills the voids underneath.
Is that all nonsense, or does he have some points?
Thanks again.
Brian

1. Probably because he laid them wrong, he obviously doesn't know what he is talking about.
2. Whoever laid them didn't use any SBR in the mix or wiggle / tap them down. Edge slabs are always the most susceptible to movement so should be laid on full concrete bed with haunching and SBR.
3. He won't get a call back in a few years, later on his patios will all fail though whether they end up with water freezing in the gaps, vermin there, rocking flags etc Bottom line is that it doesn't conform to british standards which states bedding layer should "provide uniform support"
4. Will adhere better if laid correctly on a full bed than on a spot bed, in any case if you want them to adhere best you use a wetter mix with SBR in it and or SBR bond bridge.
5. There will still be plenty of voids underneath. The only way to ensure that there aren't any is to put huge circles but when you tap it down you end up with mortar squelching up between the joints and making a mess of the face and having a hell of a time tapping it down to level because there is too much mortar underneath.


In short, he is talking bollocks.

Post Reply