Patio issue

Hi all, two months ago we had a new patio laid in our back garden, it involved lowering the whole area but things seemed to have gone ok. However we now have an issue where it doesn’t look like the cement in between the slabs has not set correctly. Almost straight away you could see that there was a gap between the grouted cement and the edges of the slabs. To my horror I’ve since found out that just a moderate amount of sweeping results in the cement breaking up, and to my horror I found out yesterday that I can actually lift out the cement in junks using my fingers, if I hold the cement between my finger’s it just crumbles and has no strength to it.
We are trying to get the guy back to sort this and the pooling issue we also have out, but so far he hasn’t come back.

Can anyone help us please and offer some advice as we spent a lot of money on this.

sounds like he's brushed in a dry mix. These never work. If he's that much of a cowboy to use that technique, don't hold you breath for him coming back to fix it.

here's how it should be done.

http://www.pavingexpert.com/pointing.htm

thanks for that but I don't think he used a dry mix, it's almost as if he used too much sand and not enough cement.

And I assume that using too much cement would create a similar problem also.

I used a dry mix inbetween the slabs on my new patio and it worked perfectly. After brushing it in I pressed it down further with a slim trowel and kept tpping up the level.

Even careful use of the pressure washer on the slabs didnt cause any problems. Cant remember the ratio I used though.

anyone who uses a brushed-in dry mix is not a professional and watches far too many diy programmes.

slabs are best solid bedded and some of that bedding mortar (sharp sand and cement) teased up the edge of the slab to form a joint for its neighbour.

this way, all the mortar joints are fully bonded to the bedding material.

it is not always convenient to lay slabs this way, particularly if bad weather is forecast. in this case, the next best thing is to leave the jointing recessed then point in some mortar at a later date, making sure the joints are (if needed) damped down first.