Roof condensation

[CXRAndy]

I've just found I have the same issue, very similar house (Bungalow with good insulation). I've been into the loft and I can't see any pocket vents on the felt. There are vents under the eaves all around the house but I can't get close enough to them on the inside to make sure the insulation is not blocking them. The loft roof hatch is definately not well insulated and needs improvement though there is a ladder attached to the inside of it which may impede any efforts at insulation. The loft hatch is the only thing I might try doing myself.

The rest of it I'm not in a position to have a go at doing this myself, I'm liable to cause more problems than I solve as this is my first bought house and I'm a complete novice at DIY. I have checked back on my Building Inspection and there were no reported issues in the roof space, though it mentioned the thick insulation prevented a full inspection.

I'm going to let a local firm come and give me a quote/inspection of the space in more detail. I don't want to start DIYing especially if there issues I don't recognize, one other thing I have is an Indemity Insurance policy for lack of planning/building permissions so if there has been any post build changes that are not regulated I may be able to claim some of the cost.

In the meantime is it worth putting a dehumidfier up there?

I had a newbuild bungalow done a few years back. The builders were in too much of a hurry and fitted insulation in the loft before the plastering had gone off fully. This lead to moisture in the loft, lots of it. Even the breathable Tyvec wasn't able to cope with so much. I placed large fans to circulate the air which kept everything dry until humidity of the building dropped from natural drying. It took a few weeks to achieve permanent solution.

A dehumidifier won't work in the loft because it's not sealed enough. All you'll achieve is to dehumidify the outside weather 🤣

 

[CXRAndy]

Yeah I can't get to the edge as its only boarded in the centre of the roof. I'd need crawl boards or similar to get in there. I don't mind doing some things myself but other stuff I'm leaving to a professional at least until I understand more about these issues.

Get a full face mask when you start moving around in the loft space. Trust me, you will thank me. Moving insulation away from blocked eaves vents is not difficult, like you say get some boards, padded knee protection.

I bought one of these then got paint spray grade filters https://www.ebay.co.uk/p/1604209821

 

[wiggydiggy]

I had a newbuild bungalow done a few years back. The builders were in too much of a hurry and fitted insulation in the loft before the plastering had gone off fully. This lead to moisture in the loft, lots of it. Even the breathable Tyvec wasn't able to cope with so much. I placed large fans to circulate the air which kept everything dry until humidity of the building dropped from natural drying. It took a few weeks to achieve permanent solution.

A dehumidifier won't work in the loft because it's not sealed enough. All you'll achieve is to dehumidify the outside weather 🤣

The bungalow hasnt had any changes in the at least the last 12 months, I don't know if there was condensation here before that as the previous elderly owner wasn't likely to be up and down into the loft.

I think I'm going to try the clips myself, insulate the hatch better and then let the roofing people give me an opinion on how much more substantial changes may be.

Get a full face mask when you start moving around in the loft space. Trust me, you will thank me. Moving insulation away from blocked eaves vents is not difficult, like you say get some boards, padded knee protection.

I bought one of these then got paint spray grade filters https://www.ebay.co.uk/p/1604209821

I'm definately letting them do that, longer term I do want to start collecting stuff like that to do more myself but for now I'll see how much needs doing.

I'm hoping to have more substantial work done before next winter, for this one its a few basic changes and checks to get me through.

 

[CXRAndy]

The bungalow hasnt had any changes in the at least the last 12 months, I don't know if there was condensation here before that as the previous elderly owner wasn't likely to be up and down into the loft.

I think I'm going to try the clips myself, insulate the hatch better and then let the roofing people give me an opinion on how much more substantial changes may be.

It's not uncommon for moisture to appear in cold winter months. Small amount of heat bleeding into the roof void condenses creating moisture. These still freezing days, the airflow is non existent. So you either have to create natural draft from low to high with pocket vents, eaves vents and ridge vents or use mechanical ventilation, eg fans. There are two basic types of roof, warm roof and cold roof. Most house with lofts are cold roof design. You must try and keep all heat and humidity from the main house out of the loft.

My next newbuild I sealed the ceilings on the second floor with polythene membrane before plasterboarding. I was surprised by the statistics of how much interstitial moisture passed through the plasterboards into the loft from the main house. That's why I added the polythene.. my building inspector was mightily impressed with my attention to detail and doing the correct works. I wished in hindsight that a had upgraded to foil back insulated plasterboard too for the ceilings.

I also added a MVHR system throughout the house to control humidity, save on heating and provide clean filtered air even when all the window vents were shut

 

[SpokeyDokey]

I've just found I have the same issue, very similar house (Bungalow with good insulation). I've been into the loft and I can't see any pocket vents on the felt. There are vents under the eaves all around the house but I can't get close enough to them on the inside to make sure the insulation is not blocking them. The loft roof hatch is definately not well insulated and needs improvement though there is a ladder attached to the inside of it which may impede any efforts at insulation. The loft hatch is the only thing I might try doing myself.

The rest of it I'm not in a position to have a go at doing this myself, I'm liable to cause more problems than I solve as this is my first bought house and I'm a complete novice at DIY. I have checked back on my Building Inspection and there were no reported issues in the roof space, though it mentioned the thick insulation prevented a full inspection.

I'm going to let a local firm come and give me a quote/inspection of the space in more detail. I don't want to start DIYing especially if there issues I don't recognize, one other thing I have is an Indemity Insurance policy for lack of planning/building permissions so if there has been any post build changes that are not regulated I may be able to claim some of the cost.

In the meantime is it worth putting a dehumidfier up there?

I was under the impression that loft hatches were supposed to be left uninsulated to allow a small amount of warmth into the loft space to help prevent pipes freezing.

Not an expert so I may well be wrong.

 

[wiggydiggy]

It's not uncommon for moisture to appear in cold winter months. Small amount of heat bleeding into the roof void condenses creating moisture. These still freezing days, the airflow is non existent. So you either have to create natural draft from low to high with pocket vents, eaves vents and ridge vents or use mechanical ventilation, eg fans. There are two basic types of roof, warm roof and cold roof. Most house with lofts are cold roof design. You must try and keep all heat and humidity from the main house out of the loft.

My next newbuild I sealed the ceilings on the second floor with polythene membrane before plasterboarding. I was surprised by the statistics of how much interstitial moisture passed through the plasterboards into the loft from the main house. That's why I added the polythene.. my building inspector was mightily impressed with my attention to detail and doing the correct works. I wished in hindsight that a had upgraded to foil back insulated plasterboard too for the ceilings.

I also added a MVHR system throughout the house to control humidity, save on heating and provide clean filtered air even when all the window vents were shut

Good advice. I just measured and I'll need at least 80 vents. Gonna wait for the roof people now as they may have more advice.

I was under the impression that loft hatches were supposed to be left uninsulated to allow a small amount of warmth into the loft space to help prevent pipes freezing.

Not an expert so I may well be wrong.

I'm not sure I have any pipes at all in the loft, it's all under the ground floor. Looking at the loft again I may go for a new hatch completely. The hatch I have is wooded single piece less than 1inch deep with a gap around the edge.

I'll ask em for that, plus anything else I can afford for now and get saving so next October I get some proper work done.

 

[SpokeyDokey]

Good advice. I just measured and I'll need at least 80 vents. Gonna wait for the roof people now as they may have more advice.



I'm not sure I have any pipes at all in the loft, it's all under the ground floor. Looking at the loft again I may go for a new hatch completely. The hatch I have is wooded single piece less than 1inch deep with a gap around the edge.

I'll ask em for that, plus anything else I can afford for now and get saving so next October I get some proper work done.

Don't you have a water tank up there?

 

[wiggydiggy]

Don't you have a water tank up there?

For hot water? I've only got a combi boiler, there's no water tank. New boiler in Dec (£2.5k) drained my emergency repair money so I need to just keep an eye on what I'm buying.

 

[SpokeyDokey]

For hot water? I've only got a combi boiler, there's no water tank. New boiler in Dec (£2.5k) drained my emergency repair money so I need to just keep an eye on what I'm buying.

Cold water?

Or is everything direct from mains?

Older 1970's bungalow here.

 

[wiggydiggy]

Cold water?

Or is everything direct from mains?

Older 1970's bungalow here.

All from mains. House is from 1985 according to the survey, planning permission was granted in 1979 though so it was very nearly a 70s bungalow! Very little in the loft as the hatch is a bit small and I struggle to get anything bulky in there.

 

[lazybloke]

I was under the impression that loft hatches were supposed to be left uninsulated to allow a small amount of warmth into the loft space to help prevent pipes freezing.

Not an expert so I may well be wrong.

The pipe in my loft has thick tubular foam insulation, and it's under nearly 30cm of rockwool. That sucker aint freezing!

The loft hatch was uninsulated and used to suffer from condensation on the underside - I fixed that by adding two inches depth of polystyrene to the top, plus draught proofing. I also sealed all pipe & cable penetrations.


Am now happy that I've significantly reduced heat loss into my loft... I just wish I could reduce heat loss through the solid exterior walls. That's gonna be ££££

 

[CXRAndy]

The bungalow hasnt had any changes in the at least the last 12 months, I don't know if there was condensation here before that as the previous elderly owner wasn't likely to be up and down into the loft.

You would know by the look of the wood, with dark staining on the timbers from mould growth

 

[wiggydiggy]

You would know by the look of the wood, with dark staining on the timbers from mould growth

I haven't noticed any myself, but thats partly why I've invited the experts in so to speak so any issues I don't notice can be raised. I'd like them to use a moisture sensor on some of the beams to be sure.

The issue only really occured after I had the heating on for 12+ hours a day last week at 16c / 17c / 18c. When I've gone back to my normal evening use of 14c / 15c I noticed a significant improvement in how much was there when I've checked this morning.

I'm hoping some relatively simple fixes like some felt pocket vents and a new hatch (or insulate my current hatch) will remedy the situation for now until I can afford to have more extensive work down.

 

[gbb]

Went up in our loft the other day, droplets of moisture all over the plastic membrane.
Its always been that way in our house afair. Even when we had just 50mm loft insultion it happened, now we have around 300mm, it still happens

 

[wiggydiggy]

Went up in our loft the other day, droplets of moisture all over the plastic membrane.
Its always been that way in our house afair. Even when we had just 50mm loft insultion it happened, now we have around 300mm, it still happens

Yeah I may be over worrying the problem as many people here and elsewhere are saying it can be a common issue and though needs managing, as long as the loft is getting a chance to dry I think (hope!) it will be ok.

What bothers me more is me trying to sleep at night, and I'll a hear drop fall and start worrying about it and not be able to sleep. Solution there might to put a carpet over the boarded floor and making sure to periodically check it for mold etc