Giving a wooden floor the best chance against rot?

[CluelessDIYer1]

In that case i think i've not explained myself too well.

One end of the joists goes in to the house wall itself. Like so...



You'll notice the air brick has been blocked there. It's been freed off now.

Anyway, the other end of those joists rest on the sleeper wall in the centre of the room...



You can see sections of joist & floorboard that are wet/damp.

It was my understanding that the entire lot could be removed (joists from the walls & floorboards) & then just replaced with same product in same location, but this time better protected against damp (such as wrapping ends in visqueen).

I think you may have thought we had no sleeper wall? My fault i guess - we do have one.

Hope this helps to give a better idea.

 

[CluelessDIYer1]

Oh, also, out of interest ......

Would having a 'proper' fire help with air flow underneath?

My thinking is that with a fire going, it'll be sucking oxygen in (hence pipe in photo) & will be getting the air moving better. Also the heat should help.


This is all by the by as 1) we're in a smoke controlled zone (yes i know there's smokeless fuel) and 2) the approach to manage the walls i don't think will lend itself to having a proper fire - Oldroyd XP studded plastic membrane over the walls is what we've been advised to use by one chap (not necessarily Oldroyd, but something similar).

 

[AronSearle]

Floorboards
VCL
Joists
In that order.

Joists to sit on DPC wherever they contact the brick.

Also if lifting floorboards it would be silly not to install insulation between joists IMO.

Whenever the concrete floor was installed (likely later on in the building life), pipes to allow cross ventilation through the slab to the underfloor should have been installed, if you cant provide cross ventilation there is a risk of damp pockets of air, so provide as much ventilation through other walls as you can.

 

[CluelessDIYer1]

From discussing with others there's a bit of a shout for concrete beams.

I do like this idea, though i do have my concerns about it. I think all things considered, replacing like for like would be best. Shame as i like the idea of the concrete beams.

Insulation between the joists. I'm guessing here you're talking about cut up sections of Kingspan 8x4 sheets? I wonder how you'd get them to stay there between the joists? Unless you did something like nailing 8x4 boards to the bottom of the joists to give some sort of 'pocket' which you then fill with insulation?

Whenever the concrete floor was installed (likely later on in the building life), pipes to allow cross ventilation through the slab to the underfloor should have been installed, if you cant provide cross ventilation there is a risk of damp pockets of air, so provide as much ventilation through other walls as you can.

I'll let you off since i type a lot, so you probably just never saw it but ...

Under there right now are 2 air bricks to the rear, but the vent is not a full air brick size as it's a 2" (guessing) by 2" square pipe that leads through the dining room solid floor out the back.
There are 2 air bricks to the front of the living room, 1 to the front of the hall & 1 to the side of the hall.

I know the diner was built in 2000. The kitchen on the other hand is still on the same ground it always was, yet it is (or at least feels & sounds) solid.


I was thinking today - i would've thought they'd feed in air from the side, under the kitchen & into the diner floor. Connecting piping which then leads to the living room floor. I guess this idea is stupid otherwise they would've done it.



I was also thinking of getting a proper fire (it'd have to be smokeless). My theory is that it'll dry the chimney stack out (i'm not saying it's wet, but it was meant to be used!) and in the process it'll be sucking in air from underneath the floor which should get the air circulating better (my theory, i'm not saying it's a correct one).

 

[endecotp]

There are various ways to hold insulation in place. One option is some sort of netting fixed to the bottom of the joists.

 

[AronSearle]

Having a leaky building and a roaring fire would help keep things dry, as long as you are happy living in a draught place that will be hard to heat or cold when there is no fire going.

Personally I like living in the 2000s not the 1900s.

 

[CluelessDIYer1]

Well we're getting the leak sorted but I'm not sure how you know about that since it's in the bedroom & I don't remember mentioning it on a forum lately.

As for draughty - the suggestion has been to ADD air bricks. This obviously results in more air coming in. It's the trade off.

Also not sure why you think it'd be cold when the fire isn't going?? That's what Central heating is for. Such as at my mums house - winter time the fire is always on (as she gets free fuel) & as for upstairs - the radiators do their job. Works well & fuel bill has come down since her fire was installed.

So I'm not sure I get what angle you're coming from.

 

[AronSearle]

Leaky = airleaky.

Draughty, no the suggestion is the add air bricks to the underfloor, not the occupied space, vcl under the floorboards stops draughts coming up.

That's what Central heating is for. Such as at my mums house - winter time the fire is always on (as she gets free fuel) & as for upstairs - the radiators do their job. Works well & fuel bill has come down since her fire was installed.

Well clearly her bills will come down if she gets free fuel.

Most people have to pay for firewood, open fires with air leaky buildings are very fuel iniffecent.

 

[CluelessDIYer1]

Where is the air leak though? Surely it would be no different to how it is now? The fire also wouldn't be open. I wouldn't have one of those. It'd be one of those modern multi stove things.
I've only seen my mums but her flue runs up the chimney & everything else is blocked off. We feel no draught. We don't hear any draught either.

 

[AronSearle]

In air leakage terms, softwood floorboards on joists are about as airtight as a sieve.

 

[CluelessDIYer1]

Ah right.

Still, i think we're kind of getting carried away a little here. We're hardly talking about how we'll be living in an igloo with those temperatures.

Before we started ripping everything apart, the place was warm & not draughty. The carpet was down. There was no problem as far as draughts & coldness go.

So replacing like for like as far as the floorboards go & putting in a fire, i don't really think that's going to turn the house into an ice cube. I know i don't know much about DIY stuff but i'm quite sure of that. Ok it may not be air tight, but then being air tight would present its own problems. My mum was paranoid about any little draught & would block up all of it. It presents its own problems.

But don't misunderstand me - i'm grateful for your response.

 

[AronSearle]

Ah right.

Still, i think we're kind of getting carried away a little here. We're hardly talking about how we'll be living in an igloo with those temperatures.

Before we started ripping everything apart, the place was warm & not draughty. The carpet was down. There was no problem as far as draughts & coldness go.

So replacing like for like as far as the floorboards go & putting in a fire, i don't really think that's going to turn the house into an ice cube. I know i don't know much about DIY stuff but i'm quite sure of that. Ok it may not be air tight, but then being air tight would present its own problems. My mum was paranoid about any little draught & would block up all of it. It presents its own problems.

But don't misunderstand me - i'm grateful for your response.

Heat radiates.

That means you will lose as much through your floor as your roof through radiation.

Would you leave your loft uninsulated?

I can understand peoples unwillingness not to rip up to insulate, but it seems daft not to insulate between the joists if you already have to open up the floor and will have free access, you will easily make back the money, though not as quickly if you use expensive rigid foam insulation (but you still make it back), energy prices will only go up.

And creating airtightness does not mean preventing ventilation, it means being able to control it and only provide it when needed.

 

[CluelessDIYer1]

Obviously this would be something we'd discuss with whoever is out doing the work, but it was that stuff I thought you was referring to - Kingspan or similar, cut into appropriate sections.

As it's not this then what insulation were you meaning?

 

[AronSearle]

Mineral wool, held in place by wire mesh.

Rigid foam costs more, so payback will take longer, but if you plan to stay there, it will work out better over time.

 

[CluelessDIYer1]

Mineral wool, held in place by wire mesh.

Rigid foam costs more, so payback will take longer, but if you plan to stay there, it will work out better over time.

Wow, really? I must say i'm surprised at your suggestion.

I'd have thought if anything was going to soak in moisture then that stuff would be it.

But yes, we are intending on staying there. If we weren't then we'd have probably tried to jump ship by now, or at least looked into it. The way the market is though & what's available in the area, we're going to make do & stay here.