Condensation returnd in loft

[Stotty1]

Hi, a couple of years ago I had an issue with condensation in the loft. We fixed the problem by installing felt lap vents: https://www.amazon.co.uk/dp/B00M9ILJPG/ref=cm_sw_r_u_apa_fabc_0bMYFbF6HRYMA?_encoding=UTF8&psc=1

I have just been into the loft and was greeted by condensation (not as bad as a couple of years ago but still pretty bad).

I fitted a new airtight loft hatch and a nuaire drimaster heat PIV unit this year which has been brilliant at preventing condensation in the rest of the house, but could this be the reason for it returning in the loft?

We are due to have a new heating system fitted in January do you think that will make the condensation worse as hopefully the house will be hotter than it currently is?

Thanks
Carl

 

[KenGMac]

Have a look @ this boards "Floors Stairs and lofts" section

Especially

CONDENSATION IN LOFT (ANSWERS)

Ken.

 

[Stotty1]

Have a look @ this boards "Floors Stairs and lofts" section

Especially

CONDENSATION IN LOFT (ANSWERS)

Ken.

Thanks Ken, good thread.

We have followed a lot of these pointers over the last couple of years and seemed to have had some success.
I was just shocked to find condensation this year as the only thing I can think that has changed since last year was fitting the PIV unit, so was just curious on peoples thoughts as to whether the unit is possibly to blame?

Thanks

 

[KenGMac]

Stotty, good evening again.

May be worth thinking about the number of vents you have in place now. As apposed to the volume of loft space you are venting?

One way ahead?? install more vents?

Ken.

 

[Stotty1]

Stotty, good evening again.

May be worth thinking about the number of vents you have in place now. As apposed to the volume of loft space you are venting?

One way ahead?? install more vents?

Ken.

Good evening Ken

I think that will be my next task, install more lap vents as a start and maybe even look at getting the soffits replaced as a future improvement.

Thanks for your input.

 

[KenGMac]

Stotty, good evening again.

Do you have eaves that protrude outwards over the external walls of the property?

If so?? it is possible to install so called "Soffit Vents" they come in various forms, the most common is a circular pattern that can be retro-fitted, and provided the loft insulation does not fill the eaves then that could be a way to improve cross flow ventilation?

Or? install some specialist vented roof tiles, these are mounted as tiles so should allow a better flow of air, they are also available as ridge vents?

Ken.

 

[Stotty1]

Stotty, good evening again.

Do you have eaves that protrude outwards over the external walls of the property?

If so?? it is possible to install so called "Soffit Vents" they come in various forms, the most common is a circular pattern that can be retro-fitted, and provided the loft insulation does not fill the eaves then that could be a way to improve cross flow ventilation?

Or? install some specialist vented roof tiles, these are mounted as tiles so should allow a better flow of air, they are also available as ridge vents?

Ken.

Hi Ken

Yes our eaves protrude over the external walls, I think we already have some vents in our soffits (little slots all the way along), but the soffits look pretty old so I was thinking more modern soffits may do a better job.

I will look into the vented ridge tiles as we were going to look at getting our ridge tiles re-pointed next year as we noticed the mortar has came loose in a couple of areas.
So it may be a good time to replace some with vented ones.

Thank again.

 

[KenGMac]

Stotty, good evening again.

If you have these "peripheral strip vents" a quick fix is to ensure that the installers who "placed ??" the insulation in the roof space did not jamb the insulation into the eaves?

These guys simply do not have a clue at times, they shove the glass wool right into the eaves, I asked one guy and he was trying to stop the draughts meant to vent the roof from making the house colder?? a reasonable rational there somewhere ??

bottom line is that if the eaves are stuffed full, asimple fix would be to remove this areas insulation??

Ken.

 

[Stotty1]

Stotty, good evening again.

If you have these "peripheral strip vents" a quick fix is to ensure that the installers who "placed ??" the insulation in the roof space did not jamb the insulation into the eaves?

These guys simply do not have a clue at times, they shove the glass wool right into the eaves, I asked one guy and he was trying to stop the draughts meant to vent the roof from making the house colder?? a reasonable rational there somewhere ??

bottom line is that if the eaves are stuffed full, asimple fix would be to remove this areas insulation??

Ken.

Cheers Ken

That is a good point, I did pull all the insulation back from the eaves a coupe of years ago but only in about a third of the loft space, the water tank prevents access to the rest of the loft.
We are having a combi boiler fitted in January though so as soon as the tanks are removed I will go along the rest of the loft pulling back the insulation.

Hopefully that will be enough to prevent the condensation this winter.

Thanks for all your useful tips.

 

[JP_]

I had this problem in new extension - roof was soaking wet and dripping with condensation. I installed loads of roof vents like you have, but also found a leak in the ducting from the kitchen extractor. Do you have a bathroom extractor going through the loft? A tiny gap can let in loads of very humid air.

 

[Stotty1]

I had this problem in new extension - roof was soaking wet and dripping with condensation. I installed loads of roof vents like you have, but also found a leak in the ducting from the kitchen extractor. Do you have a bathroom extractor going through the loft? A tiny gap can let in loads of very humid air.

Thanks for the reply jonbey,
Yeah the vents are good and have worked really well for the last couple of years,
we currently don't have an extractor in the bathroom, it is on our very long to do list though

 

[Stotty1]

So just had another look, and even though I pulled all the new insulation back i never pulled back the old brown insulation that is underneath, I'm hoping if I pull all that back it may help further with the condensation.

I guess you should be able to see the white of the eaves all the way along the inside of the loft?

 

[KenGMac]

Stotty, good evening again.

In effect yes, clear all the older insulation out, if you have perimeter vents, what you are looking for is daylight when you are in the loft and looking at the eaves. A lot of lofts I have been in they are positively draughty.

Ken.

 

[JohnD]

you can trim it with a big pair of wallpapering scissors, then it won't flop back.

start by opening up a few on each side so you get a through draught. The loft should feel dry, cold and draughty

 

[Stotty1]

Good evening Ken

Thank you, I could see daylight in some areas, I will go around moving all the old stuff way back until daylight is visible all round.

Thanks