Terrible experience with this outfit.
Terrible experience with this outfit, originally from Pontypool and now based in Pontnewynydd. The walls which they tanked were breached and began to leak after just over a year, and they refused to rectify the problem at their own cost.
We also discovered to our horror that the guarantee they sold us to cover the tanking was very specific and didn't actually cover that type of application of the tanking system.
The main wall in the tanked room was plastered by DTS and the plaster is now hollow, cracked, damp, and falling off. The condition of the room belies the fact that any damproofing measures were taken at all. All the plaster has to be taken off again.
Plaster they applied to an external wall in a bedroom is also extensively cracked and hollow.
Three of the four humidistat fans DTS installed have stopped working properly and, in one case, replacement has been made very difficult as they mounted the fan before plastering the way and plastered around the fan casing. The shape and model of fan is no longer available.
I would advise spending a little more for the services of a proper builders firm. You could save a lot of money in the long run by not having to pay for the work to be done twice. Maybe you'll be lucky and nothing will go wrong, but if it does and you need DTS to rectify their work, that's when you could realise what a huge mistake you've made.