I'm planning on laying slate flags for my patio and beside my house (mid terrace, built around 1910). As I am a DIY'er I'm following the recommendation to individually bed the flags onto a semi-dry mix and to use bonding on the back of the flags to prevent movement that might occur due to my inexperience in laying the flags. The laying course will be on top of 75mm compacted Dtp1.
Previous owners had installed a soak-away in the clay soil as well as building the paving level over the level of the DPC so moisture has been getting through the walls and I'm a bit paranoid about preventing the ground staying wet post renovation. To address this I'm dropping the paving level well below the DPC 100 - 150mm haven't decided as a bounding block fence that starts above this level complicates matters.. and installing linear drainage (away from the house) with a fall of 1:40 which I think will be sufficient to account for the riven slates rough surface.
I've been reading up on the different pointing options and both the Romex product featured here, and the EasyJoint product look like a very convenient solution (EasyJoint requires less preparation and somewhat less care it seems) however both of these are porous.
Does anyone think that the pointing being porous will be a problem given the above proposed laying structure and the fact that this area butts right up to the house?