Loft hatch, boarding and insulation questions

Spir4L

stuart45 said:

That's insulation at rafter level. 

Yeah! I guess in your opinion it would be useless to do both the rafter level insulation and the floor joists insulation tho?

WIAWSNB

Spir4L said:

With the upgrading of the loft insulation thickness to a minimum of 270mm it will become warmer on the lower levels of the property, which will automatically leave the loft space a lot colder during the winter months, during a prolonged cold spell of frost and snow this can increase the chance of layers of vapour freezing on top of and under the existing roof membrane and on top of and under the existing roof tiles/slates, when the frozen vapour eventually melts as the temperature warms up it can condensate and create temporary condensation droplets which drop off the membrane and into the loft space.
To combat temporary condensation and further insulate the loft space, you can either install a (50mm Celotex loft wrap to the roof rafters to create an R Value of 2.25m2K/W) or at the very least run a dehumidifier in the loft space at the end of every prolonged cold spell.

I'm pleased they 'justified' their rafter-insulating suggestion, and there is some truth to what they say above - it'll likely stop the odd drip. But, there are some very good and simple reasons to not go for this, as it runs the risk of serious harm. And it doesn't work...

Just keep the 'loft' thoroughly ventilated, so cold and dry, and your stored goods should be fine (yes, wrap them to keep the odd condie drip away!).

What is the purpose of a 'roof'? Is it to keep your house warm? No, it's to keep rain off the house. What is the purpose of a 'ceiling'? Is it to keep rain from your house? No, it's to keep your house warm.

What is the purpose of an umbrella? To keep rain from yer 'ead. What is the purpose of a woolly hat? To keep yer 'ead warm.

Is it possible to have a roof/ceiling that does both? Yes, it's called a 'warm' roof, and needs to be designed that way. You don't have one. You have just a 'roof'

Your loft space must - MUST - be kept well ventilated to the outside, or you risk serious harm from condensation which will come up from the house as warm moist air, and condense out in the colder loft space. Left to become excessive, and over time, this will likely lead to timber rot. You aren't going to stop moist air coming up from the house, so the answer is to safely vent it away. That means a good draught up there, quite literally the draughtier the better. Will that make it cold? Yup, indeedie. Is that a problem? No, at least not unless you have water tanks up there. 

The under-rafter area is not designed, and was never intended, to have insulation added to it. If you add insulation there, you run the risk of not only reducing the ventilation to these rafters - so any condie won't be dried off - but also trapping that condie behind it where it can't be seen, so you won't be able to even monitor what's going on behind it, as some folk on this forum have found to their cost (soggy under-rafter insulation).

And will under-rafter insulation even make the loft 'warmer'? Not really, because the howling winter winds will still be flying through that loft doing its job, and you cut that draught down at your peril. And where would this extra warmth come from anyway? The house below? A heater? 

Q - you go out on a cold windy winter's day with yer brolly. It keeps the rain away, but it's still bludy cold. You have a choice - you either pull on a woolly hat ('loft insulation'), or you line the underside of your brolly with fleece (dodgy rafter insulation). Which one will make you warmer?

So, yes, insulation to the ceiling. But leave the rafters alone. Double-check - in fact prompt them - to not block the ventilated eaves with their extra loft insulation. Once done, either drape a tarp over your boxes as mentioned before, or - better - put clothes in bin bags, vacuum them and tape them up. 

And, when you are up there on a breezy day, do check there is a good draught, and nod sagely when there is, knowing that your loft and your possessions are going to be fine. 

Years ago I had the task of going up into my in-law's loft to fetch their stuff down as they were selling. It was all in cardboard boxes, most not even closed. It was a breezy winter's day, and I was astonished at how windy and bludy cold it was up there.

But everything was absolutely fine - pictures, paintings, toys, magazines, electronics items, you name it. 

WIAWSNB

Spir4L said:

This is an example of a Celotex Wrap work that shows in CheckaTrade, from the picture I would say the insulation is at the rafters level, probably with a certain amount of gap

That has been (I hope) carefully designed. 

If you line your loft with rigid insulation like that, ensuring that the rafters above are not filled, and the eaves ventilation on both side not blocked, and that there's a through-wind-path in one side, up the roof, over the top, down the other side, and out the opposite eaves, then fine - you have created a new 'room' that is now part of the house. 

But, it'll still need 'heating'. And, some controlled ventilation. 

You would not allow a cowboy to do this work, or you risk your rafters rotting away out of sight. 

Albermarle

Spir4L said:

stuart45 said:

Because cold air is constantly coming in with the required ventilation. The insulation in the joists stops most of the heat getting into the roof space anyway. It's cold, damp air that gets through. That's why you need ventilation.

Thanks, so in conclusion there's no way to make the loft space a bit warmer in the winter and cool in the summer to avoid damaging what I store there? But also to use it as a hobby room (for diy for example)?

One alternative is to have the loft space properly converted into a habitable room. So a loft conversion with a proper staircase, floor strengthened and all fire regulations covered. You could use this as a bedroom, and advertise it as a bedroom when you ever come to sell the house, if you have all the right paperwork. It is an expensive job ( £50K +) but it can add a similar value to the house, in the right house/area.

I believe there are also companies, that will do a job that goes half way. So boarded out, insulated, couple of Dormer windows, central heating radiator etc. ( £10k ??) 
However no proper staircase, just a loft ladder and no properly strengthened floor.
So definitely not for use as a bedroom, or for storing very heavy items, and not safe for a children's playroom ( not an easy escape in case of fire)
Probably a grey area if an adult uses it for DIY/hobbies just in the daytime. Some people would be happy to and some maybe not . I think opinions differ. A friend did this and his teenage son used it for drum practice.

stuart45

The firms I know that do these cheap conversions normally stick in a Velux rather than a dormer. A lot of people go for this cheaper method. Worth bearing in mind that this kind of work doesn't normally attract time served tradesmen. They often cut out some important roof timbers like binders, hangers and struts to get more space.

Albermarle

stuart45 said:

The firms I know that do these cheap conversions normally stick in a Velux rather than a dormer. A lot of people go for this cheaper method. Worth bearing in mind that this kind of work doesn't normally attract time served tradesmen. They often cut out some important roof timbers like binders, hangers and struts to get more space.

Sorry I meant Velux windows.

What is your opinion in what these types of conversions can be used for in practice? I guess people do use them for a home office, hobbies etc , even though I guess the floor is not strengthened at all/not fully anyway?, plus of course there is a fire escape issue. 

stuart45

Albermarle said:

stuart45 said:

The firms I know that do these cheap conversions normally stick in a Velux rather than a dormer. A lot of people go for this cheaper method. Worth bearing in mind that this kind of work doesn't normally attract time served tradesmen. They often cut out some important roof timbers like binders, hangers and struts to get more space.

Sorry I meant Velux windows.

What is your opinion in what these types of conversions can be used for in practice? I guess people do use them for a home office, hobbies etc , even though I guess the floor is not strengthened at all/not fully anyway?, plus of course there is a fire escape issue. 

I know loads of people that have done it, and they all seem to think it was worth it. Occasionally, you get some deflection in the ceiling below. It's not really a great selling point though. A proper conversation is a lot more money initially, but as you said, the price is normally more than recouped in a sale.
I can understand why people do it, and a decent ladder, and boarded out loft with easy access does give you a lot of good storage space. When you've got a small trap hatch with difficult access, and you have to risk going through the ceiling to get the Christians decorations down which are full of fibreglass, it's the sort of place you don't want to go into. Whereas when it done up a bit, it's more likely to get regular use.

Spir4L

WIAWSNB said:

Spir4L said:

This is an example of a Celotex Wrap work that shows in CheckaTrade, from the picture I would say the insulation is at the rafters level, probably with a certain amount of gap

That has been (I hope) carefully designed. 

If you line your loft with rigid insulation like that, ensuring that the rafters above are not filled, and the eaves ventilation on both side not blocked, and that there's a through-wind-path in one side, up the roof, over the top, down the other side, and out the opposite eaves, then fine - you have created a new 'room' that is now part of the house. 

But, it'll still need 'heating'. And, some controlled ventilation. 

You would not allow a cowboy to do this work, or you risk your rafters rotting away out of sight. 

This is a picture from a work they completed that is exactly what they offered me, so the insulation on the ceiling and the additional rafters insulation.

Anyway I guess you have said enough in your other post to convince me not to go for it and just do the insulation at the ceiling level and boarding.

Spir4L

Albermarle said:

One alternative is to have the loft space properly converted into a habitable room. So a loft conversion with a proper staircase, floor strengthened and all fire regulations covered. You could use this as a bedroom, and advertise it as a bedroom when you ever come to sell the house, if you have all the right paperwork. It is an expensive job ( £50K +) but it can add a similar value to the house, in the right house/area.

I believe there are also companies, that will do a job that goes half way. So boarded out, insulated, couple of Dormer windows, central heating radiator etc. ( £10k ??) 
However no proper staircase, just a loft ladder and no properly strengthened floor.
So definitely not for use as a bedroom, or for storing very heavy items, and not safe for a children's playroom ( not an easy escape in case of fire)
Probably a grey area if an adult uses it for DIY/hobbies just in the daytime. Some people would be happy to and some maybe not . I think opinions differ. A friend did this and his teenage son used it for drum practice.

Yeah I was quoted about £58k + VAT for a full conversion, including also setting up for an extra toilet and heating/radiators, about 2 years ago. It might be even more now.

I was looking for something in between, as you say, in the grey area, to get extra storage but also a place where I could spend a few hours doing the odd diy job, that is why I got these two quotes from both pretty well reviewed companies.
They shared with me also the options of adding plasterboards on top of the rafters insulation and as well one or two windows and yes the total was coming at about £10k/11k with both, but without any central heating radiator.

I would be curious if you could share an example of a company that will do a job that goes half the way!

Spir4L

stuart45 said:

Albermarle said:

stuart45 said:

The firms I know that do these cheap conversions normally stick in a Velux rather than a dormer. A lot of people go for this cheaper method. Worth bearing in mind that this kind of work doesn't normally attract time served tradesmen. They often cut out some important roof timbers like binders, hangers and struts to get more space.

Sorry I meant Velux windows.

What is your opinion in what these types of conversions can be used for in practice? I guess people do use them for a home office, hobbies etc , even though I guess the floor is not strengthened at all/not fully anyway?, plus of course there is a fire escape issue. 

I know loads of people that have done it, and they all seem to think it was worth it. Occasionally, you get some deflection in the ceiling below. It's not really a great selling point though. A proper conversation is a lot more money initially, but as you said, the price is normally more than recouped in a sale.
I can understand why people do it, and a decent ladder, and boarded out loft with easy access does give you a lot of good storage space. When you've got a small trap hatch with difficult access, and you have to risk going through the ceiling to get the Christians decorations down which are full of fibreglass, it's the sort of place you don't want to go into. Whereas when it done up a bit, it's more likely to get regular use.

This would be exactly my use-case, and it's what I thought I was going to get from these two quotes.