MegaSack DRAW - This year's winner is user - rgwb
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I spent some hours yesterday pointing up bits of the front of our house. Used pre-mixed mortar and one of those large grouting guns as some of the cavities were quite deep. Just been to start cleaning off the brickwork now, and the new stuff is the consistancy of baked sand. 🙁
What may I have done wrong, so I don't make the same mistake again. Perhaps,
- Weather was too hot and dry, (south facing) dried up the mix too quickly.
- Fairy Liquid plasticiser not such a good idea after all.
- Something else.
Thanks.
Add PVA glue to the mix
PVA in mix + Wet the wall first?
I did wet the wall first, but it was such a warm sunny day,it pretty much dried straight away. Hmm, perhaps this should have been my clue to leave it to another day. I got the proper plasticiser from the hardware shop which it says has the same adhesion properties as the PVA, so I'll probably stick with that.
5 litre bottle should last me about 2 lifetimes 😀
you did everything wrong, using a pointing gun for a start, buying premixed mortar, adding fairy liquid to the mix. start by wetting the wall. mix up silver sand and cement, i go 2;1 with a bit of plastisicer and a very small amount of water. my mate goes 1;1, with no plastisicer. if its deep, go over it once, pressing it well in with a finger trowel, stopping about 10 mm below the edge of the joint, allow to go off. add a top layer when not quite dry. try to be neat, any smearing will look ok when wet, but looks terrible once dry.
sharpness of sand in readymix mortar and ratio of sand,cement would also be factors
what spchantler said !!
Do not use bloody pva! For exterior work and rendering you should use sbr
I went with the pre-mixed stuff as I assumed that would be more reliable. Thanks for the tips, but as for,
there's more chance of me winning tomorrow's MTB olympic gold. I've still got some paint to clean off anyhow, so will make sure it's all ship shape on completion.try to be neat
edit, What's SBR??
You bought that **** from B&Q? 🙁
the only time ive seen premixed mortar set propper was when i left an open bag in the rain ....
that stuff really is gash.
as above pre-mixed mortar is rubbish. but also you need to wet it down 3 times a day for it to go off in this weather. mortar doesn't 'dry' it is a chemical reaction, and in needs water for it to happen
Never in a million years would I use silver sand!! Far to fine an aggregate! Yellow building sand (not red too many impurities) and cement, sachet of feb mix just to make it more workable, and gauge it or you'll have varying colours!!
Make sure joints are raked out well and actually hose down the wall to remove the dust. Never point on "wet" brickwork or it will smear.
Also what type of pointing? Bucket handle, flush etc etc.
Well I've done it again this morning, following all the tips. It's looking a lot better and it's a cooler, damp day here today so hopefully no more problems. Managed not to make too much of a mess of the bricks either.
Flush pointing, and no, not a B&Q premix, Hanson brand from Weaverham Hardware emporium.
I've always got a bag of Hanson ready mix in a sealed bucket in the van. Pretty decent stuff for general use