Water stain on joists in roof - Loft boarded out recently

[JosephGourvenec]

Hi all,

Looking for some advice on if I should be worried or if this water staining is happening because of the recent frost/cold -0 degree temperatures in the UK.

We had our loft boarded out and floor put in for a man cave for myself mid December 2011 so about 4 or 5 weeks ago.

We've been hit with hard rain with gale force winds and really low temperatures over last few weeks.

Which I believe is causing this issue.

The Issue:

Because of the weather I have noticed that the 2 main beams / joists that support the roof are getting water stained. This has happened in really bad rain and wind and now when really cold.

Images attached

I have insulated the loft with 5cm/50mm thick polystyrene in each roof partition with a 5cm/50mm gap between the roof tiles + membrane to the polystyrene insulation too for the circulation of air.

When looking up in to the roof space I can see the water drops on the back of the polystyrene with the 5cm gap to the tiles.

What I wondered is because I am now up in the loft (I.e. Man Cave) and I can now see this happening anyway.

Or it is just a combination bad weather & insulation creating this.

Any advice would be grateful, any questions I can try answer.

Image 1 - Taken on 14-1-2012

Roof Water Stains 1

• JosephGourvenec
• 17 Jan 2012
• 1

Roof Water Stains 1

Image 2 - Taken on 17-1-2012

Roof Water Stains 2

• JosephGourvenec
• 17 Jan 2012
• 1

Roof Water Stains 2

 

[tim00]

Cant tell what i'm looking at - it could be a hip rafter or a purlin or something else - is the pic the right way up? Google roof terminology and ID the member.
Can you see or access the roof area?
Do you recall any staining in that, or any other, area, before boarding it?

 

[JosephGourvenec]

Hi Tim,

It is a purlin 100%.

is the pic the right way up? yes

Think that you're looking at it dead on from the bmiddle of the roof / floor area.

Google roof terminology and ID the member. ??? I don't understand.

Can you see or access the roof area? Yes

Do you recall any staining in that, or any other, area, before boarding it? No as only went in the loft to put more junk in it.

Came home today to reply to your message and it has dried up mostly, prob because of the 11'O C we've had in Leeds today.

Do you think I should be worried or just the cause and effects of the weather and roofs in general?

Cheers,
Joe

 

[RedHerring2]

Do you have low level and high(ridge) level ventilation?

You'll need it.

 

[catlad]

Condensation more ventilation required as already stated.

 

[JosephGourvenec]

Thanks RedHerring2 & catlad,

Just to be clear

Is that on each side of the roof kind of a vent style?

Cheers,
Joe

 

[catlad]

Yes both sides, vents are going to depend on what type of roof you have ?

 

[tim00]

Ventilation might be an issue, but thats not condensation, it's probably blown rainwater. Thing is, being a purlin the water could have penetrated on any of the rafters resting on the purlin, and travelled to that spot.

Get as close as you can to that general area on the roof coverings, and see if you can spot any obvious discrepancies - perhaps take some exterior roof pics.Do you have any roof penetrations - vents, roof lights or roof windows, cracked or missing tile or slate?
Roofing felt will typically carry any blown moisture down to discharge in the gutter, unless it is missing or penetrated.

Given that the exceptional, recent wind circumstances might be a one-off, it will still pay you to track down how it happened.

 

[JosephGourvenec]

Thank you all very much so far and at the weekend I'll try get some extra pics of roof etc.

Cheers,
Joe

 

[Alastairreid]

Ventilation might be an issue, but thats not condensation.

Agree! deffo rain penetration.