New patio - concrete between slabs breaking up

Pythagorous

no offence taken - i thought as much!

lindos90

This is a couple of years old, but may still be interesting to read, it does raise the issue of damp proof course level too, which you should check (for your house and conservatory if the patio butts up to either)

http://www.diynot.com/forums/viewtopic.php?t=118354

Tucker

Wow hang on. From the pics that base looks like type 2 MOT to me.

That's exactly what they should use and is the right base for the job. It is not gravel, it's tarmac rippings, usually 40mm pieces down to dust.

The key is that is should be properly compacted using a heavy duty whacker. The slabs can then be laid on a mix of sand and cement using the 5 dab method.

The base looks the right gear, it just depends if it's been compacted, if so there's nothing wrong there.

macman

Apart from the absence of any visible dabs of mortar-the slabs have just been dropped onto the base-of course they're going to move.

frank.hopper

Yeah looks like type 2/ scalpings to me, nothing wrong with the base if it's been wacked but it must be blinded out, either with whin dust or sand.


http://img.skitch.com/20100707-ecq7y6jcxc4jj8i5569jcjkpcp.jpg


You might get away 3x2s with that, but not those little 18" ones.

Pythagorous has said there's movement, the pointing is doomed until it's corrected.

jimbo_the_jetset

wallbash wrote: »

I always use a sharp sand/cement base. But for pointing , I get myself a radio something to sit on , small pointing trowel . Takes me a long time. But when finished , will resist a power washer.

Brushing in a mixture , might well be fast , but will require maintenance.

I was thinking of using a really wet mix, maybe even just a cement water grout and using a tiling grout float to finish the joints. I suppose it will depend on the type of slab as to the ease of wiping it off........maybe a test on a slab first......

wallbash

using a really wet mix,

NO !!! the reverse ..... a really dry mix.

A wet mix will stain the slabs , look really terrible.The test , pick up some in your hand, squeeze, if it stays in a ball but does not stain your hand , thats correct.

wallbash

Use a 'chopping' action , side of trowel , really compact the mortar.Then finish/smooth off.

Pythagorous

lindos90 wrote: »

This is a couple of years old, but may still be interesting to read, it does raise the issue of damp proof course level too, which you should check (for your house and conservatory if the patio butts up to either)

http://www.diynot.com/forums/viewtopic.php?t=118354

Thanks for pointing that out I hadn't even considered that. Could well be a major issue as the patio level is now right up to the patio door!:eek:

ormus

must say it looks a lot like a DIY job to me. it doesnt look like a very pro job.
i always use sharp sand for slabs. and a dry mix for the grout.