moisture coming through membrane in new roof

[huwy123]

hi there,

About 3 months ago I had a loft conversion and new roof - i.e. membrane and new tiles.

Whilst poking about in the loft today I noticed that there is a fair bit of moisture coming through the membrane. This is evident in a few different parts of the roof. (see pics)

This looks like a serious problem to me and I wondered if I should get a 3rd party to review the work first of all to ensure I don't get fobbed off.

Obviously I will be contacting the company that did it but I wondered what would be the best course of action. I appreciate any advice on this!

Cheers,
Huw


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[noseall]

Looks like condensation to me and nowt to do with the roofing company.

 

[Mw Roofline]

Everyone gets condensation in lofts just as it starts to get freezing outside and we all whack up the thermostat.

Just make sure any loft insulation is pulled away from the edges, it should be shoved into the corners.

 

[Mw Roofline]

* Should not

 

[Alastairreid]

How is the roof space ventilated?

 

[freddiemercurystwin]

Looks like condensation to me and nowt to do with the roofing company.

If the membrane is breathable then there's shouldn't be any condensation!

 

[freddiemercurystwin]

How is the roof space ventilated?

You don't need any additional ventilation if the membrane is breathable.

 

[Toproofer]

How is the roof space ventilated?

You don't need any additional ventilation if the membrane is breathable.

Would that not depend on insulation in loft,hot air could be getting in loft space causing condensation, I've had problems with tyvek felt before!! So don't use it anymore.

 

[freddiemercurystwin]

By enlarge the fitment of a breathable membrane should do away with the need for additional ventilation. There will always be situations that break the rule though.

 

[noseall]

Looks like condensation to me and nowt to do with the roofing company.

If the membrane is breathable then there's shouldn't be any condensation!

Wanna bet on that Freddie?

For those of you that think 'breathable' membrane means that they will deal with ALL scenarios of condensation criteria, then think again.

A lot will struggle when temps are very low and moisture within the home is very high.

 

[huwy123]

Thanks for all the replies - I really appreciate the advise.

Having read up on it I minded to agree - its condensation. We do have a "perma-vent" breathable membrane but I guess its not breathable enough and I should be looking at extra ventilation.

I was up there lagging some pipes which I've read will help. Maybe I'll investigate fitting soffit vents into existing plastic soffit. Any other suggestions please let me know!

Thanks again,
Huw

 

[catlad]

Warm air rising up from the cavity its a common place to see condensation.

 

[huwy123]

Ah that explains why its only forming at the bottom.

What would you recommend I do to sort this out? Soffit vents?

 

[catlad]

Well if you can reach you could try stuffing some insulation in the top of the cavity and see if that helps.