Internal door frame head - necessary?

[Olf]

As a part of renovation we're planning to add UFH and MVHR. I removed the existing door frame and floor to lintel opening is 2015 mm.

1981 mm (height of standard 78" door) + 25 mm (extra floor thickness to accomodate heating) + 10 mm (gap for the airflow) = 2016 mm

I can trim the door a bit,  but it seems that 6mm is generally the maximum recommended, regardless of the manufacturer.

 

So the questions is: how important is the frame head in this case?

With the wall made of conrete blocks with concrete lintel (which I really don't want to move) I shouldn't worry about any flexing - is the idea of replacing proper head with a stripe of 6mm plywood (just to have something to stick the upper part of the door stop to) sensible?

[Onoff]

Morning,

 

Correct me if I'm wrong but it sounds like you are just adding UFH on top of an existing floor? That 25mm is what, some sort of thin, thermal insulating board?

 

Is there any insulation under the floor say like 150mm worth of pir?

 

If not you'll just be leeching heat downwards. It'll work but your heating bills will be sky high.

 

As for the 6mm ply stuck to the underside of the lintel I can't see why not. Maybe with something a bit flexible like CT1 to allow movement given the two materials.

[ProDave]

Actually in my house I did not bother with the top door stop, just a flat head.

 

The logic being the side door stops will stop the door swinging too far, nobody can see through the gap at the top by not having a door stop, and it increases the venltilation area for the mvhr.

 

And Oak is expensive.

[Olf]

7 minutes ago, Onoff said:

Correct me if I'm wrong but it sounds like you are just adding UFH on top of an existing floor? That 25mm is what, some sort of thin, thermal insulating board?

 

Apologies, failed to mention - it is upstairs, so heat going down not (less of) an issue.

 

6 minutes ago, ProDave said:

The logic being the side door stops will stop the door swinging too far, nobody can see through the gap at the top by not having a door stop, and it increases the venltilation area for the mvhr.

 

And saves work at the same time Great idea!