Terrace with porcelain stoneware tiles (Questions about installation)

Hello,

as the house construction is slowly nearing completion, I would like to start building a terrace. Some questions/uncertainties have come up where you might be able to help us a bit.

We want to build a terrace of about 7m (W) x 3.50m (D) with porcelain stoneware slabs (60x60, 2cm thickness). We want to border the terrace with binder stones (14x14x15 cm).

The following procedure we have in mind:

- compact about 20cm of RC material while already creating a slope of 2cm per meter
- the terrace should be flush with the lawn at the end
- we protect the house wall with a dimpled membrane
- the binder stones will be set in concrete
- on the RC material comes about 12 cm of trass drainage cement and on the tile an adhesion slurry
- slabs will be laid with cross joints using 5mm cross joint spacers
- finally the joints will be closed with joint mortar

Now our questions:

In most terrace videos (often staggered laying) from Hornbach, OBI, etc., the border (e.g., lawn edging stones) is always done first and then the slabs are laid inside. With a cross-joint laying method, we are concerned that the last row of slabs in the end will not fit (ok, can be cut) or – even worse – some free space will remain. Therefore, we wanted to leave one side “open” and only embed this side with the binder stones in concrete once we have reached the last slab. Is there any objection to this?

On some information sites, the house wall was also protected with masonry barrier tape (so that if the terrace subsides, the house wall is not pulled along) or edge insulation strips. Does it matter whether you use a dimpled membrane, masonry barrier tape, or edge insulation strips?

Should one also lay fleece membranes over the RC material? I have seen this once as well.

Should an expansion joint (e.g., with edge insulation strips) be installed every 3-4 meters?

Are there any other general concerns/advice/tips from you regarding the construction of a terrace with porcelain stoneware?

Thank you in advance

Regards Julia & Robert

Hello you two, if you really want the perfect laying pattern without cutting, you should set the binder stone afterwards, meaning stop laying two rows earlier, then measure and set. By the way, you have this problem in length and width. You don't need fleece, it's actually used as a separating layer and/or against weeds. A dimpled membrane belongs on the house wall, water collects in the edge insulation strip, it is only for inside, and you don't need a movement joint either, since the covering can move in all directions.

Thank you for your response. That helps us a lot.

Are we correct in choosing the drainage cement? We are also considering laying it directly on gravel from time to time. However, we have also read that the thinner porcelain stoneware tiles can be less stable compared to the bonded variant.

Can you save a lot of money by mixing the drainage concrete yourself? What do you need for that? Cement? Granular gravel? We have a cement mixer. Although there are ready-made mixes available at the hardware store, we will need a lot of bags for the terrace size.

Can you save a lot of money by mixing the drainage concrete yourself? What do you need for that? Cement? Granular gravel? We have a cement mixer. There are also ready-made mixes available at the hardware store, but for the size of the terrace, we will need numerous bags.

Mixing yourself is significantly cheaper (50-60%). You only need gravel and cement for that, mixed in a ratio of 4 to 1. For your terrace size, however, you will need at least 3-4 big bags of gravel; each weighs about 750 kilograms, which you should consider for delivery and storage.