Help! Laying Slabs

[billytheghillie]

I need some words of wisdom from the PW mass. I am trying to lay slabs and am struggling to get a level base. Any hints or tips would be welcome.

[fenboy]

Knock wooden pegs in across the area , use a long level and knock pegs down until the are all level at the height you want them (allow a little fall away from the house).

 

lay base up to the top of the pegs and jobs a good one

[chady]

How big an area??

[billytheghillie]

12ftx10ft

[ben0850]

Are you laying the slabs on sand? If so set up two parallel kerbs (could be rails or similar) and ten use an appropriate length of timber with a notch cut at either end (notch the same depth as your slabs) as a screeding board to help with levelling your base.

[chady]

+1

 

And mix some cement into the sand and use sharpe/grit sand

 

Are you laying the slabs on sand? If so set up two parallel kerbs (could be rails or similar) and ten use an appropriate length of timber with a notch cut at either end (notch the same depth as your slabs) as a screeding board to help with levelling your base.

[Gimlet]

If you're laying on screed you need screed rails, though its not the way I'd lay slabs. In my opinion laying any but the smallest slabs on screed is the best way to get rockers.

If you mean you're struggling to stone up level, the simplest way to check and one of the best is to use a dipper. Knock in a few pegs along each side of the area to be slabbed at exactly the level of the finished slabs. Mark a stick with the thickness of the slab plus the depth of the mortar bed then stretch a string line across the pegs and check the depth with the stick. If the mark is above the string line you have a high spot to rake off and if it is below, a low spot to make up. Move your string along the pegs and keep dipping and raking level as you go. To be really thorough string a couple of diagonals as well and you will have a very accurately levelled base. Whack it and get laying.

[Browning 425 clay hunter]

Why not hire a whacker plate, put MOT down then grit sand on top then whack it flat. Use a spirit level to check your base is flat. Then joint up if you are leaving a gap or get brushing in sand to fill the small gaps if not using cement.

[saddler]

Get a couple of Lambrinis inside them and you'll be good to go...

 

Oops...thought ya said slags....better get to Specsavers....

[robbiep]

As an ex-groundworker, I'll just say that I hate, with an absolute passion, the practice of laying slabs on sand, or of brushing sand/cement dry into the gaps as pointing.

 

Get your base set up first - MOT(crusher run, 30mm to dust) or similar, with a slight fall. For 12 ft you need 1-2 inches of fall, doesn't need to be a ski slope.

Then, lay the flags on mortar. 5 good dabs under each flag (4 corners, 1 centre). Good large blobs. More if particularly large slabs. Use a rubber mallet to tap to the level you want. You want to have to hammer them down a bit, if it's just a couple of light taps then really you should be using more mortar.

When all dry (leave it for 48 hours after putting the slabs down) use mortar again for pointing.

 

Do it right, and you won't need to touch it for 15-20 years. Bodge it, and you'll be at it again in 5 years.

Edited June 12, 2014 by robbiep

[Mentalmac]

As an ex-groundworker, I'll just say that I hate, with an absolute passion, the practice of laying slabs on sand, or of brushing sand/cement dry into the gaps as pointing.

 

Get your base set up first - MOT(crusher run, 30mm to dust) or similar, with a slight fall. For 12 ft you need 1-2 inches of fall, doesn't need to be a ski slope.

Then, lay the flags on mortar. 5 good dabs under each flag (4 corners, 1 centre). Good large blobs. More if particularly large slabs. Use a rubber mallet to tap to the level you want. You want to have to hammer them down a bit, if it's just a couple of light taps then really you should be using more mortar.

When all dry (leave it for 48 hours after putting the slabs down) use mortar again for pointing.

 

Do it right, and you won't need to touch it for 15-20 years. Bodge it, and you'll be at it again in 5 years.

haha wish I used this advice.

I made a patio so blooming secure you could park a tank on it without any movement.

[ditchman]

Just bear in mind if you are laying slabs up to the house DO NOT LAY THEM LEVEL OR ABOVE THE DAMP PROOF COARSE............when i bought my house had a really bad damp problem in the kitchen...the previous owner had gone too close to the DPC......

[turbo33]

As an ex-groundworker, I'll just say that I hate, with an absolute passion, the practice of laying slabs on sand, or of brushing sand/cement dry into the gaps as pointing.

 

Get your base set up first - MOT(crusher run, 30mm to dust) or similar, with a slight fall. For 12 ft you need 1-2 inches of fall, doesn't need to be a ski slope.

Then, lay the flags on mortar. 5 good dabs under each flag (4 corners, 1 centre). Good large blobs. More if particularly large slabs. Use a rubber mallet to tap to the level you want. You want to have to hammer them down a bit, if it's just a couple of light taps then really you should be using more mortar.

When all dry (leave it for 48 hours after putting the slabs down) use mortar again for pointing.

 

Do it right, and you won't need to touch it for 15-20 years. Bodge it, and you'll be at it again in 5 years.

 

Its THE only way to do it. Good post Robbie, should be a sticky, will save people loads of grief

[jloc]

OK folks seeing as this is a slab thread what are your thoughts on paving over and old patio?

 

Got about 45sqm of 2' x 2' slabs that are looking rather tired.

 

Is it a case of lifting them all or can I leave them in place and fit sandstone over the top.

 

Thought please??

 

Cheers

 

J

[robbiep]

Ideally, you'd lift them up and replace. But that big an area is going to be a lot of work to lift.

But ... has there been any movement/settlement under them previously ? Do they have a bit of fall on them to drain ?

If those are good, then go for it.

[flynny]

As an ex-groundworker, I'll just say that I hate, with an absolute passion, the practice of laying slabs on sand, or of brushing sand/cement dry into the gaps as pointing.

 

Get your base set up first - MOT(crusher run, 30mm to dust) or similar, with a slight fall. For 12 ft you need 1-2 inches of fall, doesn't need to be a ski slope.

Then, lay the flags on mortar. 5 good dabs under each flag (4 corners, 1 centre). Good large blobs. More if particularly large slabs. Use a rubber mallet to tap to the level you want. You want to have to hammer them down a bit, if it's just a couple of light taps then really you should be using more mortar.

When all dry (leave it for 48 hours after putting the slabs down) use mortar again for pointing.

 

Do it right, and you won't need to touch it for 15-20 years. Bodge it, and you'll be at it again in 5 years.

Bang on , the trades mans way, the proper way, the mortar on your slabs should look like the number 5 on a dice,

 

Not your b&q /let's have a go at it DIYer lay on sand technique,

 

Atb

 

Flynny

[chrisjh]

As an ex-groundworker, I'll just say that I hate, with an absolute passion, the practice of laying slabs on sand, or of brushing sand/cement dry into the gaps as pointing.

 

Get your base set up first - MOT(crusher run, 30mm to dust) or similar, with a slight fall. For 12 ft you need 1-2 inches of fall, doesn't need to be a ski slope.

Then, lay the flags on mortar. 5 good dabs under each flag (4 corners, 1 centre). Good large blobs. More if particularly large slabs. Use a rubber mallet to tap to the level you want. You want to have to hammer them down a bit, if it's just a couple of light taps then really you should be using more mortar.

When all dry (leave it for 48 hours after putting the slabs down) use mortar again for pointing.

 

Do it right, and you won't need to touch it for 15-20 years. Bodge it, and you'll be at it again in 5 years.

 

+1

[shootnfish]

Personally i would only spot bed the ex council type slabs 50mm thick 2x2 or 3x2 . If you have sandstone or similar i would recommend you lay them on a solid mortar bed as this will be more stable and stronger than spot bedding as you will have no voids under the slabs. It also makes jointing the slabs quicker and easier.

nearly all slab suppliers and manufactures recomend against spot bedding.

Edited June 12, 2014 by shootnfish

[evo]

simple answer is just tarmac it bud,,lol,,I never want to see a flag again as long as I live,well lay them again,

 

what started as building a pond for my disabled son with a bit of a patio around it has now(£3500 later) ended up totally redesigning my back garden and I have lost a lot of time out shooting,

 

I basically dug down 2 1/2 foot to put some concrete footings in,then I layed a double skin brick wall 12ft x 7ft on top of the footings, I then crush and run the whole area to be flagged and used a wacker plate to tamper this down,

 

once this was done I then mixed in a barrow a mix of 4 too 1 sand and cement to lay the flags on,i did not spot them as I wanted a solid bed for the flags to sit on rather than 5 spots of sand and cement,

 

once I had completed building all the walls I then dug out a pathway to join the near house patio to the pond patio and also put crush and run down and tampered this also,

 

well today I have finally finished all the flagging,now all I,ve got to do is point them all up,this will probably take me two days at least,

 

wish I only had your area to do, and to top it off I have had to barrow all the bricks ,crush and run,sand and cement,flags the lot through the bloody house because due to building an extension on the side of the house we have no rear access,

 

have you ever felt " WHY THE HELL DID I START THIS ",,,,anyway pond is finished,all the walls are now built all the flagging has now been completed just coping stones to go on the top of the walls now and that's it,,,she has her back garden done and I,m off shooting,

 

heres some pictures and I,ll put some up 2moro of it now finished,,well except for the coping stones,

 

boy am I glad its nearly there, I,ve done this on my own and its taken me nearly six weeks

 

here are the pics

 

I,ll put some more pics up 2moro of the full work now its finished including both patio areas

 

hope this helps

 

atb Evo

[SHOOTEMUP]

simple answer is just tarmac it bud,,lol,,I never want to see a flag again as long as I live,well lay them again,

 

what started as building a pond for my disabled son with a bit of a patio around it has now(£3500 later) ended up totally redesigning my back garden and I have lost a lot of time out shooting,

 

I basically dug down 2 1/2 foot to put some concrete footings in,then I layed a double skin brick wall 12ft x 7ft on top of the footings, I then crush and run the whole area to be flagged and used a wacker plate to tamper this down,

 

once this was done I then mixed in a barrow a mix of 4 too 1 sand and cement to lay the flags on,i did not spot them as I wanted a solid bed for the flags to sit on rather than 5 spots of sand and cement,

 

once I had completed building all the walls I then dug out a pathway to join the near house patio to the pond patio and also put crush and run down and tampered this also,

 

well today I have finally finished all the flagging,now all I,ve got to do is point them all up,this will probably take me two days at least,

 

wish I only had your area to do, and to top it off I have had to barrow all the bricks ,crush and run,sand and cement,flags the lot through the bloody house because due to building an extension on the side of the house we have no rear access,

 

have you ever felt " WHY THE HELL DID I START THIS ",,,,anyway pond is finished,all the walls are now built all the flagging has now been completed just coping stones to go on the top of the walls now and that's it,,,she has her back garden done and I,m off shooting,

 

heres some pictures and I,ll put some up 2moro of it now finished,,well except for the coping stones,

 

boy am I glad its nearly there, I,ve done this on my own and its taken me nearly six weeks

 

here are the pics

 

I,ll put some more pics up 2moro of the full work now its finished including both patio areas

 

hope this helps

 

atb Evo

 

You Have done an excellent job of that and your family must be so proud of you they are indeed very lucky. thanks for sharing these pictures

[evo]

thanks for that shootemup,,

 

as promised took a few more photos today of the back garden and both patio areas and the pond

 

and here is the pond with my fish now in it

 

atb Evo

[shootnfish]

Very nice , nice pond too. Do you think you will seal the paving later on?

[Oxon T]

I agree with this. Full mortar bed is stronger. Also 5 spot method can apparently stain through sandstone slabs where the mortar blobs are. With Full bed it won't show up as it is even.

 

Personally i would only spot bed the ex council type slabs 50mm thick 2x2 or 3x2 . If you have sandstone or similar i would recommend you lay them on a solid mortar bed as this will be more stable and stronger than spot bedding as you will have no voids under the slabs. It also makes jointing the slabs quicker and easier.

nearly all slab suppliers and manufactures recomend against spot bedding.

[Fisherman Mike]

I need some words of wisdom from the PW mass. I am trying to lay slabs and am struggling to get a level base. Any hints or tips would be welcome.

You need to visit the following site...its brilliant...

 

http://www.pavingexpert.com/

[evo]

Very nice , nice pond too. Do you think you will seal the paving later on?

I,m going to wait until all the flagged area has been pointed then I,ll seal it all,

 

cheers Evo

You need to visit the following site...its brilliant...

 

http://www.pavingexpert.com/

that's a cracking site and full of information

 

atb Evo