Low adhesion filler (like mortar)

[MortarThePoint]

Mortar is fantastic stuff for filling load bearing gaps but is tricky when the gap is very thin and is a nuisance to mix when you only need a small amount. One great property of it is it is relatively easy to rework if things go wrong.

 

I've got some thin gaps (3mm) I want to fill with something with the be benefits of mortar. It would ideally be gun-able straight from a tube. There are loads of grip fill adhesives, but I don't want it to grip much or adhere much like mortar doesn't to DPM.

 

Is tile adhesive the right choice, or is there something better?

 

I'm laying some Hardie Backer across the cavity on top of a gas membrane so don't want to get in a situation where I cock it up and it's not reworkable. Door cill then sits on outer leaf covering end of Hardie Backer and will screed over the rest. Cold bridge kept low as 12mm Hardie Backer is L=0.19.

[Makeitstop]

Sounds like you only want to hold it in place, so if that's the case, something simple like a caulk would likely do it.