Old School House (photo added)

[waz_aarp]

Hi,

I'm looking at purchasing an old school house built around 1847.

The majority of the school has been renovated with the exception of a 12.5mtr x
7 mtr classroom. This room is double height with no 1st floor, we're looking at
putting a mezz floor in at one end to create a master bedroom.

I need some advice on insulating this building.

The current owner has removed some of the original wooden flooring to expose the timber joists, the joists are infilled with what the owner said is lime concrete. After searching the net it looks as if this may be pugging?

I was thinking that I could remove the wooden floor boards then lay 25mm kingspan across the joints before putting the engineered flooring directly on top this?

For insulating the walls there seems to be a number of ways to insulate. I'm unsure of the most cost effective option, I was thinking about installing wooden batterns (unsure of size) placing kingspan insulation between the
banterns then installing plaster board over the top.

Will I need a vapour barrier?
Do you leave a gap between the insulation & the brickwork?

Any advice on the the above will be much appreciated.

Regards,
Darren

 

[Gareth Hughes]

This isn't supposed to be as stupid a question as you might think, but why do you want to insulate it?

 

[waz_aarp]

The only stupid question is the one that isn't asked

The reason for wall insulation is to retain heat and reduce heating costfuel bills.

For the floor, I wanted to also add some heat retention but mainly I'm wanted to control potential damp rising.

 

[Gareth Hughes]

How thick are the walls? the idea that just because they're solid, they leak heat is a complete nonsense.
As for damp "rising", especially "potentially", I refer you to another recent thread.
(I live in an 1880 terraced house with 9 inch solid walls and no insulation except in the loft, and although I can tell when it's winter and summer [boiling tonight], neither I, nor my bank account, currently feel the need to turn it into a modern airtight [with trickle vents so I don't suffocate just by breathing out] box)
Welcome to the forum, though, look around at what's been said before.

 

[Moo]

The majority of the school has been renovated

That could mean a lot of things, not all of which would be good for the building. I'm puzzled about that infilling between the exposed joists: it sounds as though the current owner has replaced a suspended ground floor with something solid, thus eliminating any sub-floor ventilation. Judging by what I remember of past threads, that seems a recipe for encouraging damp.
Perhaps them as knows will give an opinion about that?

 

[Hatster]

I'm wondering whether the current owner has run out of money to finish the job, and whether this is a sign that corners may have been cut already...

 

[CHRIS]

If you insist on insulating I would consider this

http://www.natural-building.co.uk/pavadentro_renovation.htm

You don't use breather membranes with foil backed insulation such as Kingspan but you must use the correct foil tape (I am not recommending this type of insulation just answering your question)

 

[waz_aarp]

How thick are the walls? the idea that just because they're solid, they leak heat is a complete nonsense.
As for damp "rising", especially "potentially", I refer you to another recent thread.
(I live in an 1880 terraced house with 9 inch solid walls and no insulation except in the loft, and although I can tell when it's winter and summer [boiling tonight], neither I, nor my bank account, currently feel the need to turn it into a modern airtight [with trickle vents so I don't suffocate just by breathing out] box)
Welcome to the forum, though, look around at what's been said before.

Hi, I can't remember the wall thickness but will take note the next time I visit, thanks for other info I have a look at that thread.

I'm puzzled about that infilling between the exposed joists: it sounds as though the current owner has replaced a suspended ground floor with something solid, thus eliminating any sub-floor ventilation.

The present owner has done nothing more than remove a section of flooring to reveal what is underneath.

I'm wondering whether the current owner has run out of money to finish the job, and whether this is a sign that corners may have been cut already...

I was impressed with what work had already been completed, my assumption is that they have been renovating the property over the last 10 years on a very small budget, reason for selling the property is that they intend to become missionaries so I'm guessing they already do alot of charity work which isn't that well paid

If you insist on insulating I would consider this

http://www.natural-building.co.uk/pavadentro_renovation.htm

You don't use breather membranes with foil backed insulation such as Kingspan but you must use the correct foil tape (I am not recommending this type of insulation just answering your question)

.

Thanks for the info.

 

[DaveBrigg]

A couple of thoughts. If using battens and kinspan inside, bear in mind that this will probably affect window and door frames, which may need to expand to fit the new wall thickness.
Limecrete will provide some insulation already (although less than kingspan of course) and is breathable, thus reducing the likelihood of damp when comapred to concrete. Are there signs of damp in the floor joists at all?
If you are set on fitting a new, engineered floor then adding insulation beforehand is not quite such a big deal. However, most people here have managed to retain the original flooring, and there are plenty of threads giving advice on possible treatments to make old boards look stunning. If the only reason for taking them up is to add insulation, the cost and disruption could outweigh the benefits. It would save you having to cut an inch off each door for a start. :wink:

 

[chuckey]

It is unclear whether you are going to lay your kingspan over the joists and the air between them or over the joists imbedded in the limecrete. If the floor is laid over the kingspan which is only supported over the joists, as you put more weight on the floor it will crush the kingspan. The result would be that the whole floor will bend and drop under points of high loading, such as under the setee legs or piano legs. I would not recommend this at all.
The idea of leaving the joists imbeddded in lime crete does not seem a good idea. As we all know wooden joists need under floor ventilation to keep their moisture level down. As for the lime crete I wonder what this meant to do? It looks to me like a case of rotten or insubstantial joists and as a bodge to to remove the spring from the floor, some one just filled the underfloor void with limecrete.
Frank

 

[waz_aarp]

I've added a photo to try and expalin better



you can see the section of wooden floor that has been removed, the top of the timber joist can be seen with the concrete infilled between them. The concrete is level with the top of the joists. At each end there is two sections that are just concrete, no joists visible.

I was intending to insulate and then lay a new wooden floor or tiles, I doubt if the missing section could be replaced without looking a bit out of place, so I thought about utilising the old wooden floor elsewhere.

I hope this clears up a few of the questions?

 

[Hatster]

Ah, if they've been renovating over many years, that's very different! I get the impression there are developers running out of money and having to sell at the moment...

Looks like it's going to be a lovely house when you're finished!

I don't know whether you'll be able to find it / them, but I think there have been a number of Property Ladder / Grand Design episodes with people adding mezzanine floors to halls and churches more and less sucessfully, and you might find it helpful to watch some of those to see what works in that type of space and what doesn't. There was one where mezzanine floors had actually made the rooms terribly dark.