philp

Hi The render of the chimney on my bungalow parted company with the brickwork. I believe that this was due to the chimney getting damp (it was unused and had no air holes at the bottom). I have now added air bricks and now must re-render the chimney. I have removed all the old render and gouged out the cement between the bricks(1/2 inch). Because I am a novice I intend to add battans to the chimney to help gauge the thickness of the render. I am aiming at a thickness of 16 Mil. The first coat will be 10 mil. My first intention was to use a lime mix. However I spoke to a builder and he told me to use a straight forward 1:3(Cement:sand) mix using a special plasterers sand. He told me to add PVA glue and treat the brickwork first with PVA. I asked him if 1:3 could cause cracking and he said that it would not. I want to do things his way because it makes my life somewhat easier, I can stick 16mil battens in place and approx render the first 10. Fill the rest in later and take the batttens out and fill them in all with the same mix. Should I really be using lime to do this job(I dont like using lime because its pretty nasty stuff). On the other hand I dont ever want to go through the pain of rendering the chimney again, so I would like it to last the next 30-40 years. Thanks for reading this, any comments appreciated.