Got a problem on a thincoat job we did 18 months ago.
We thincoated 3 houses on same street by the book and no problems at all in Johnstone’s. Then one of the customers had a timber frame extension built which was renderboarded ready for us. We had to obviously use Johnstone’s to match the rest of house we did previous. The boards were dry the temperature was right and no rain as we did it. We used 6mm bead ,high flex basecoat etc. then 18 months passed with no problem until we got called back. You could literally pull the render off in one spot with no effort. The board was clean underneath. We sent Johnstone’s rep down. He said it was wrong board and there a massive problem In market.
The board was resistant multi rend board which is a magnesium oxide one. When looking on google there seems to be a lot of s**t with magnesium boards nationwide. Resistant spec that you can use k rend, Parex, fassa etc etc.
we spoke to k rend rep who said it’s not approved board even though resistant say it is. Spoke with fassa who say don’t go near it . Surely the answer has got to be the fitter should of used knauf aquapanel or rcm . The fitter obviously don’t want to replace board. So we ended up getting a rep from resistant out. They said any other system would work apart from Johnstone’s because it’s cheaper and there something In there basecoat. Argued with me that it’s approved everywhere. They also said just the one side were it’s failed needs re render and the other two sides will be fine. They said because the board is clean underneath it’s been rendered wrong of course. After digging more I found that building control stated no warranty on magnesium boards in 2020. Surely if we pull it off and use another manufacturer it will happen again. All thincoat render we use are similar. The customer wants warranty which Johnstone’s said if it was rcm or aquapanel it should last 30years.
surely it needs to be boarded in the correct board this time.
Any advice off be appreciated
We thincoated 3 houses on same street by the book and no problems at all in Johnstone’s. Then one of the customers had a timber frame extension built which was renderboarded ready for us. We had to obviously use Johnstone’s to match the rest of house we did previous. The boards were dry the temperature was right and no rain as we did it. We used 6mm bead ,high flex basecoat etc. then 18 months passed with no problem until we got called back. You could literally pull the render off in one spot with no effort. The board was clean underneath. We sent Johnstone’s rep down. He said it was wrong board and there a massive problem In market.
The board was resistant multi rend board which is a magnesium oxide one. When looking on google there seems to be a lot of s**t with magnesium boards nationwide. Resistant spec that you can use k rend, Parex, fassa etc etc.
we spoke to k rend rep who said it’s not approved board even though resistant say it is. Spoke with fassa who say don’t go near it . Surely the answer has got to be the fitter should of used knauf aquapanel or rcm . The fitter obviously don’t want to replace board. So we ended up getting a rep from resistant out. They said any other system would work apart from Johnstone’s because it’s cheaper and there something In there basecoat. Argued with me that it’s approved everywhere. They also said just the one side were it’s failed needs re render and the other two sides will be fine. They said because the board is clean underneath it’s been rendered wrong of course. After digging more I found that building control stated no warranty on magnesium boards in 2020. Surely if we pull it off and use another manufacturer it will happen again. All thincoat render we use are similar. The customer wants warranty which Johnstone’s said if it was rcm or aquapanel it should last 30years.
surely it needs to be boarded in the correct board this time.
Any advice off be appreciated