Mortar in a bulk gun

[R D S]

I did some pointing (or something vaguely resemblant) last weekend using a bulk gun filled with mortar.

Successfully sqeezing mortar from the gun was variable so I thought i'd take some advice before finishing the job as for the most part I was squeezing the water out then knocking the mortar out of the tube.

I was using readymix, which was somewhat sandy, I wondered if I would be better mixing my own with a bit less sand. And as for wetness, when fairly wet the stuff squeezed out well initially but it seemed too easy to separate out the water so I'm wondering if i'd be better off with a stiffer mix. And plasticiser? Will that help? I did put some washing up liquid in the mix (I saw a builder I worked with some years ago do it).

Frankly any advice would be appreciated.

Ta, Rick

[Andrew Gabriel]

I've never tried one, but I wouldn't expect it to work. Mortar shouldn't be able to flow if it's the right consistency, which is why I wouldn't expect a gun to work.

[Phil L]

I used one a few months ago and it took a while to get the consistency correct.

You need building sand, nothing sharp. Plenty of plasticiser, at least twice the amount reccomended on the bottle, and mix well, with not much water, that is to say it should be very creamy but not too wet IYSWIM.

You always end up with a compressed plug of stiff mortar when the tube's empty, this should be discarded and not re-used.

There's always some seperation of water and mortar so dustsheets would be advisable if you are doing walls etc - if you are pointing a patio, just remember to keep the open end of the tube pointing skywards

[Phil L]

They do work, and very well. I pointed a 75m patio with 12mm gaps, which took 6 bags sand and 2 cement and had it done in about 4 hours.

Doing it by hand would have taken over a full day and the end result would have been nowhere near as good - the gun injects the wet mortar down to the bottom of the joint and fills up the entire gap.

The drawback of course is that the mortar is 'like piss' and it has to be left a short while to dry up somewhat before a jointer can be run over it, and then it can be lightly brushed with a soft brush

[Mark]

An ideal mix to protect your house from water penetration for the next ? years then.