Smooth render on top of old Weathershield type coating.

[DAWNYP]

First post so please go easy on me!

We have lived in our new house for 6 months now. It is a typical 1970's style house with 4 beds approx 120 sq m.

I have a couple of queries that I hope people can advise me with.

1. Condensation upstairs. We have a severe condensation problem in all the bedrooms upstairs particularly on cold nights. I don't dry washing in the house and try to air with the windows open every day. The loft from what we can see is fully insulated and the previous people had cavity wall put in. The window reveal around my daughter window has started to crumble and we have very small areas of black mould around the window. We have booked for a plasterer to come and plaster around the window as it is back to the brick in areas. Do we need to have insulated board fitted around the window? I think we have cold bridging problems??


2. The house was painted with one of the weathershield type products about 20 years ago but it looks dated and it is started to peel in areas. We would like to have the house rendered smooth but can this be done on top of a bumpy coating like this? Also would external insulation help with the cold bridging or would we still suffer around the windows etc? Is is expensive for external insulation? How much should we expect to pay for a smooth render? Also the UPVC windows were put in 1989 would we need to change them perhaps they are not very effiicient? they do not have trickle vents so I try to lock them on the 1st setting when I can.

Thanks in advance and sorry to sound so clueless I am and hubby not sure either!

Dawn

 

[compendiumhead]

I guess that smooth render (sand & cement) won;t help with damo unless you use a lime based one. (K-Rend, Webber etc). These are breathable, but a fibreglass based 1st coat would help adhesion.

Self coloured lime based render will go over anything, and never needs painting. Though the existing coating might need stripping or at least power washing first.

Internal condension is typical in these houses. Do your windows have trickle vents? Double or single glazed? Do you have ANY air bricks blocked by the coating company? many 1970's homes had gas fires with flues, these , as chimneys, allow air to flow through the house.

Many questions..... if in doubtm, hire a dehumidifier for a week, and see how much water you get out of the place.


Good luck

 

[tim00]

Good advice above. i dont understand if your exterior is rendered or merely painted over?
If possible, hang fire with the plasterer - first be pretty certain as to what's causing the damp. Pics, interior and exterior would help us.
FWIW, when you are asking questions perhaps you would attempt to give each query a separate line - then we dont have to tease out what it is you are asking.

 

[dave1953]

Good advice above, does your bathroom, presumably upstairs, have a mechanical extractor fan with Humidistat facility, if not this is a root cause of moisture laden air travelling round your property till it finds a cold spot and will condensate when the internal surface temperature is below Dew Point. Employing a De-Humidifier is good advice, it should have a Relative Humidity meter incorporated in it, accepted Relative Humidity[ i.e moisture in atmosphere content] is 45% to 50%, anything over and you have a condensation problem.
Hope this helps