Insulating Eaves of a loft conversion - Have I messed up?

[Shock999]

Hi guys,
Have recently had an loft conversion done that has an uninsulated eves in one side for storage with a small hatch on the purlin wall for access.

The Purlin wall is insulated, but the small door seem to let in cold air.

I want to use the eves for storage, but its not insulated and gets very dusty as this side of the roof is facing the road. (the roofer had attached a roof membrane under the drafters but this doesn't do much.

here is a picture as I would describe it.(ignore the bad drawing please)
 

So, over the weekend, in my wisdom I decided to insulate the underside of the roof timber with foil insulation, and I think I have stopped most of the draft and dirt coming in. In my head there is still plenty of ventilation above the foil to keep the timber healthy? Have I thought this right?

Here is where I have added a foil .
 

here is a picture of my foil work.
 

Have I thought this right? Its nor perfect, I just wanted draft & dust to stop, it probably isn't fully wind-proof, but thats ok.

Is this going to cause issues of condensation in the roof rafters? Have I messed up?

I could have used PIR insulation between the rafters, but the hatch door is small and would have made the job very difficult. I mainly want the wind and dust to stop and am aware that the foil won't stop the cold coming in.

But now I am concerned that its going to cause condensation.
Or am I over thinking this? as there is over 100mm ventilation above the foil and the roof tiles?

[goodbyegti]

Surely it's fine. The advantage you have is that you can inspect it easily in cold weather for condensation. Perhaps by cutting a small hole in the foil and taping it up.

Edited June 17 by goodbyegti

[Dave Jones]

yes, you have blocked airflow at the eaves. It needs to freely flow under the tiles and exit the ridge.

[dpmiller]

ventilated dry ridge kit and some soffit vents

[Dave Jones]

Just now, dpmiller said:

ventilated dry ridge kit and some soffit vents

 

wont help unless the eaves insulation is removed though.

[Shock999]

15 hours ago, Dave Jones said:

yes, you have blocked airflow at the eaves. It needs to freely flow under the tiles and exit the ridge.

 

Hi this is what I wanted to ask,

 

can't the ventilation still happen behind the foil?

 

like below?

 

There is a new dry ridge installed which happened when the loft was installed.

 

There is still plenty of space behind the foil, the drafters are empty. They are only half filled with PIR after the Purlin wall?

 

[Dave Jones]

cranked ceilings are a massive pain, if you remove the insulation at the corner to allow airflow you will have a cold spot and black mould. could allways fit a single room MVHR unit to take care of the humidity.

[syne]

21 hours ago, Shock999 said:

 

Hi this is what I wanted to ask,

 

can't the ventilation still happen behind the foil?

 

like below?

 

There is a new dry ridge installed which happened when the loft was installed.

 

There is still plenty of space behind the foil, the drafters are empty. They are only half filled with PIR after the Purlin wall?

 

This is how I did mine,up to a point.

You can get eaves trays, lap vents and a dry ridge kit which will allow the passage of air and consequently allow moisture to vent away.

 

You have essentially two roof types in one, a cold roof in your eaves and a warm roof in your loft space.

As long as your eave aren't rammed to the soffits and you ridge has vents you'll probably be fine.

 

The gap above the foil, below the tiles/membrane does have to be continuous to the ridge on each rafter bay though.

So if your loft insulation doesn't have air flow to the ridge your going to want some vented tiles to provide an exit for the flow of air.