Barrier Mortar

[spawnoflard]

I have a ground floor kitchen with a cement floor that I'm going to put a screed over and apply a liquid dpm too.
There are some gaps between the cement and the wall that I don't want the screed to fill and some are quite deep.

I'm trying to find a good barrier mortar to fill them with.
Some are thin and I was thinking of just using silicon but that seemed like a bodge.

Any recomendations?

I was looking at Dunlop Rapid Repair Mortar but not sure if this is the right stuff or if it's better to mix my own.
http://www.selcobw.com/dunlop-rapid-repair-mortar-with-hydroloc-grey-5kg

 

[spawnoflard]

Going to try this additive.
A lot of the ones I found were between £40-80 which were ready mixed and seemed a good solution but I think this will do just as good.
http://www.selcobw.com/sealocrete-sealoproof-2-5-ltr