Render or Dot and Dab advice please!!!

[Hullstorage]

Right here goes:

I have reluctantly had to remove old plaster from old walls as it had blown.

Some of the brick work joints are now loose so should i render, if so what with or will the dot and dab process strenghen in anycase??

Thanks

 

[roy c]

If the walls are dry and there isn't any damp then you would be better to float and set it. You say the that some of the brickwork joints are loose. If there are any cracks then it would be best to "point" these up or mesh them or fibre tape over them set in the scratch coat you use. You have got to identify what mortar was used in between the brick work and what sort of strength it is. As you dont want to be laying something over the top of it that is stronger than existing..So it maybe lime mortar or sand and cement mortar. Is it whitish in colour and goes to powder if you scrape it with a scrapper, or quite solid and hard to scrape out.If it is the first one them it is most likely to be a lime mortar so you could put a 6-1-1 or 7-1-1 mix on float and set or you could dot and dab (depends what fittings and fixings you have on the wall) or if its sand and cement mortar I would go for (assuming that it is probablly a 4or5 to1 mix) go for a 5-1-1 or 6-1-1 float and set.You could always use a backing plaster either "hardwall" or "bonding" coat...