DIY Doctor UK DIY Forums

Hello, this is my first time... please be patient. I recently took down a lath/plaster ceiling.While the room was cleared I decided to fix a sheet of lightweight visquine to the ceiling timbers,to stop any horrible black coal dust from being blown down.When we decided to fix the new plaster boards we left the visquine in place between the boards and the timbers.Bearing in mind,that this is a bedroom and a bathroom,would their be any problems regarding condensation when the loft insulation is fitted in place between the ceiling timbers? This looks very neat and tidy from the loft space,but I'm not sure if I've created a problem,your help would be much appreciated... many Thanks.

By fitting water proof plastic sheet across each ceiling and taking care to avoid any holes, you will be doing yourself a great favour.
Most homes have a problem with water vapour.
Unfortunately, we all tend to breath and produce about 2.5 litres of water every 24 hours. Young children, dogs, people who are active can produce more.
This usually filters through the plasterboard ceilings into the loft, where it settles on the nearest cold piece of wood and in the wrong conditions can cause wood to rot.

bells

Following on from what Perry 525 has put. The vapour barrier is a good idea as long as the area above is adequately insulated. Once the area is insulated you will stop warm air migration into the loft and therefore there should not be any issues.

Hope this helps

LCL

Hi,thanks very much for comments,ref... perry 525 and lcl.I cannot guarantee the plastic was totally hole free,so I suppose some water vapour could sneak through,do you think I'm being to critical. Many thanks...

Water vapour is attracted to cold and to dry air, it abhors a vacuum and will do its best to fill it. And of course it will expeditiously move from a warm room to a cold loft.
Where your insulation raises the temperature of the ceiling surface then there will be little incentive for the water vapour to move that way - it will probably make straight for the nearest cold window and condense there.
I think you can ignore any small holes, if you do notice some while laying the insulation, then seal them with a suitable tape.

PERRY525... thanks very much for info.