New build block work

egizz983

Hello i recently sow few videos about how Ireland and uk builds new houses and have few questions .I am from eastern Europe so we do things differently how ever i would like to know more about this . So i assume all or most houses in Ireland being build with insulation inside the walls and noticed that they use plastic film on walls(or like where windows are) as well was wondering whats the reason and why i would assume that's have to do something with moisture inside the walls to escape or something . can someone give me more information on this .

Dudda

In short, yes houses in Ireland are traditionally block built. They started out as solid walls and then introduced a cavity. Over decades this cavity has gotten wider and filled with insulation. In the last few years houses are built more airtight to reduce draughts and heat loss. This involves sealing the windows to the airtight layer. The airtight layer is usually the internal plaster so you'd have a 'plastic film' which is an airtight tape and membrane around the windows that seals the windows and doors to the internal plastered walls. This helps reduce draughts and heat loss around the windows and doors.

Anything not clear or need more info let us know.

maestroamado

My comment much the same as above buy the plastic strip you see along the side of window/door is to stop moisture getting from outer wall to internal wall as at this point the wall almost touching...

I assume you in colder dry climate in Europe...

egizz983

https://www.boards.ie/discussion/comment/118732471#Comment_118732471

i think you talking about air tightness membrane and tapes here ? what i mean is plastic film between cavity walls witch i assume is to extract dampness from inside the walls so it would go outside and not inside. something like this in the image

Yes i am from cold climate zone we dont do cavity walls there at all we use big blocks(180-300mm thickness) and insulation from outside airtightness from inside .and so i am not sure why in Ireland cavity walls are popular as for me its seems to be more expensive build this way and dont see any benefit as well as in Ireland casting walls is not very popular for residential buildings witch is also way faster and price same or could be even cheaper .

maestroamado

https://www.boards.ie/discussion/comment/118732735#Comment_118732735

Do an exercise on humidity levels in there and here and it may be easier to compare...

If outer wall insulation waterproof you may very well be correct... i have no first knowledge of this...

Dudda

I follow you know. Yes that plastic is to stop rising damp. It continues across the floor and steps in the cavity of the external wall so any moisture that gets into the cavity is pushed outside not inside.

You have to remember Ireland is a very damp climate with strong Atlantic wind and rain and high humidity. Cavities and the stepped plastic - DPC (damp proof course) developed as a solution to this. The damp and mould found in some older houses is evidence of this problem