Can insulation touch the outside walls?

[Trowelblazer]

After a lot of looking I am hoping that someone can clarify this for me. I have insulated between my suspended ground floor joists with celotex. But when it comes to the question of "can the celotex touch the outside walls" some people say yes, others no.

If the answer is no then surely there is no point in insulating a floor and leaving a big gap around the outside of the room.

In my room with the joists layout and sleeper walls positioned it would mean
a big gap around the perimeter. I don't see the problem as it will touch the walls above the DPC so will not create a bridge.

Any advice or thoughts on this would be really appreciated

Thanks

 

[catlad]

I would not leave a gap as celotex does not absorb water, but if you are still worried lay a piece of dpc between the wall and celotex.

 

[JohnD]

has somebody told you it will be a damp bridge? Or a cold bridge?

Ask them why they think that, then tell us. It may be amusing.

They way you have done it will not block draughts, which are the main source of cold from suspended floors. There is no convection, and very little conduction, through a floor.

 

[freddiemercurystwin]

No gaps anywhere, any gaps caused by walls or joists not being straight etc should be filled with expanding foam. The only reason you'd leave a gap would be if the perimeter wall was wet but if were the case that needs to be addressed first.

 

[JohnD]

you can also stuff the gaps at the ends and edges of the room, where most draughts occur, with mineral wool (preferably the brown stuff treated with Ecose to avoid loose fibres). I prefer it to expanding foam. The filling should not extend below the bottoms of the joists or obstruct airflow especially round airbricks.

 

[Trowelblazer]

Thanks for the replies I appreciate it. I thought that it was a bit strange as the whole idea is to close off all air gaps.

When people tell you daft stuff like that you start to doubt what you are doing so thanks to everyone for confirming.

Happy new year