Outdoor Patio with Porcelain slabs

[Mgilesy81]

Hi,

I am new to here & stumbled across this site in my pursuit of finding the best solution for laying my patio.
After much searching on google & youtube I am lening towards the following.... [please correct me if i'm wrong or missing out any processes]

1. Excovate existing soil to required depth
2. Compacted Type 1 sub base [75-100mm]
3. Screeded bed [75-100mm] which includes a fall of 1:60 away from the house. [min 6 weeks cure before bedding tiles]

I an keen on the screed bed, as I have limited experience laying external slabs & feel it is essential for me to produce a true flat base to lay onto & using a thinner bed external adhesive.

FYI the tile dimensions will most likely be 600 or 800mm2 dimensions of the patio will be roughly 7m wide by 2.4m deep.
The patio will be based around full tiles. So minimal cutting other than a down pipe drain

So this is where i have a few specific questions

1. Do i need to use 20mm slabs if i have a well prepped base below or is 10mm sufficient?
2. What adhesive product should i use for the tiles & what bed height should i use [recommendation of trowel please]. Specific brand examples for both would be an amazing help!
3. Do i still need to use a bonding/priming solution on the back of the tiles if im using an adhesive, or do i just back butter with adhesive?
4. Do i need to add expansion joints to the screed or tiles? What would i use for these?
5. Do i need to put a drainage matt on top of the screed.

Appreciate any advise to help me along the way on my project.

 

[Steve6690]

I'm doing my own patio project, although it's slate and not porcelain but I think the method still works. Half the patio is on an existing screed and I used tile adhesive, but I extended it and the new section will be sand/cement 6:1 on an MOT type 1. I used tile adhesive as bonding/priming solution and it's rock solid. To answer your questions :

1. No. 20mm is only necessary for self supported tiles. 10mm will be fine with a full bed of mortar or adhesive underneath.
2. I used a PTB (Pourable Thick Bed adhesive) to fix tiles onto my screed. This is to eliminate any voids under the tile where water could collect and freeze. I didn't notch it at all, just poured it out in a continuous bed.
3. Just back butter. Tile adhesive will bond to porcelain
4. I would say not required - mine has been fine without
5. I didn't use a drainage mat and that particular section has been down for 5 months without issue.

Just my experience but there are pro's on here that might chip in.

 

[Mgilesy81]

I'm doing my own patio project, although it's slate and not porcelain but I think the method still works. Half the patio is on an existing screed and I used tile adhesive, but I extended it and the new section will be sand/cement 6:1 on an MOT type 1. I used tile adhesive as bonding/priming solution and it's rock solid. To answer your questions :

1. No. 20mm is only necessary for self supported tiles. 10mm will be fine with a full bed of mortar or adhesive underneath.
2. I used a PTB (Pourable Thick Bed adhesive) to fix tiles onto my screed. This is to eliminate any voids under the tile where water could collect and freeze. I didn't notch it at all, just poured it out in a continuous bed.
3. Just back butter. Tile adhesive will bond to porcelain
4. I would say not required - mine has been fine without
5. I didn't use a drainage mat and that particular section has been down for 5 months without issue.

Just my experience but there are pro's on here that might chip in.

Thanks Steve appreciate your reply. Sounds good, yes I feel matting is maybe a little overkill