Need advice on underfloor timber condition

[avangard]

Hi,

I'm planning to replace the carpet on my ground floor with a wood floor and thought I'll have a look at what's happening under the floor.

I lifted one of the floor boards and took some photos. Would appreciate if someone helps me understand if these photos look ok.

Untitled

• avangard
• 11 Apr 2013
• 1

This corner here seems a bit wet, but looks like the moisture is not going past the damp-proof course? Is there a bit of white mould growth in the bottom of the left wall, and also on the top of the right wall?

Untitled

• avangard
• 11 Apr 2013
• 1

What's this yellow growth? Seems to be affecting a few sleeper walls.

Untitled

• avangard
• 11 Apr 2013
• 1

What are these white stains on joists that lie on sleeper walls? Does it look like rot/mould?
it also looks like mortar is bridging the damp-proof course - is this a problem?

Overall, should I be concerned about anything on these pictures?
I'm also planning to install insulation between joists (rigid board or rock wool). Is it safe to install it in this state? Should I may be use some anti-rot treatment while I'm at it?

Sorry for a lot of questions, don't want to miss anything, as I might not get another chance to get there for a long time after I install the floor.

 

[Pigeon85]

Maybe helpful to you http://inspectapedia.com/sickhouse/NotMold.htm

 

[gregers]

seen a lot worse,yours doesnt look to bad.
but would take a look at the ventilation/air bricks situation.
the mold on your 1st pick on the over-site looks like some debris left and its slowly rotted away?
from your pics wouldnt say theres much to worry about but hard to tell from just few piccys.

 

[dann09]

avengard,

you are in good condition. most of your staining appears to be historical, cement stains.

As mentioned, remove all removable cellulose debris, and, if you wish, report back here, with number, size and location of air bricks.

Check that the exterior ground levels are below the DPC.

Do you have solid or cavity walls?

Can you annotate where exactly is your DPC in the pics? what material is it?

Your joists are sitting on plates -check the plates with a screwdriver for rot and decay, same with the joist tails sitting in their wall pockets.

Clip the loose cable to the joist bottom edges after your insulation work.

 

[avangard]

Pigeon85, thanks, I was actually browsing that site before I seen your comment!
I haven't found anything that looks like my pictures on the 'NotMould' page. Does it mean it is mold indeed?

It's white stains on the joists and yellow growth on bricks I'm a bit worried about. Does anybody know what it is?

 

[avangard]

gregers, I've noticed that the photos were scaled down so it's hard to see anything on them indeed.

These are in full size:
http://i.imgur.com/CVxTZCt.jpg?1 - weird yellow growth

http://i.imgur.com/uVhVJGk.jpg white growth. Close-up: http://i.imgur.com/Tt5a18j.jpg?1

http://i.imgur.com/iBrSJqp.jpg - white stains (circled in red) and bridging the damp-proof course (circled in blue)

 

[dann09]

Is your total DPC made of slate?

FWIW: you could pull a little oversite earth away from the brickwork and spray some cuprinol or similar on the brickwork and suspect timber spots.

Do what's suggested above, esp with regard to the sub-area ventilation. I've seen this kind of thing over the years, and it's no big deal just so long as you have good cross ventilation and a DPC in place.

You are still in good shape.

 

[avangard]

dann09,

I have 1 airbrick in front, about 24x17 cm and 3 in the back (24x9 cm) of this mid-terrace house.

"Check that the exterior ground levels are below the DPC." - Do you mean DPC in external walls? I'm not sure where exactly DPC is there. How do I tell?

I have solid external walls.

I was under impression that DPC on my pics is between sleeper walls and plates - gray slates & mortar. Am I wrong?

I'll try to do a screwdriver test tomorrow. The problem is that I don't have much access yet. I plan to replace the floor in summer and only lifted one floor board today to check what's the condition of the crawling space is.

Can't check everywhere, but from this photo http://i.imgur.com/3lCkzeN.jpg there doesn't seem to be any wall pockets for joists. This is the front wall. I think there's also a DPC in external walls seen, just below the plate in the left bottom corner.

 

[catlad]

If it ain,t broke don,t fix it just fit you insulation.

 

[gregers]

your 1st pic with the white mould,if you look closely you can see off cuts/remains of organic material on the oversite this will because of sitting in damp conditions enhance mould growth,but once the food source is used will probably just die out.as ive said imo it looks perfectly fine,but just clear any debris up and knock a few holes through any solid sleeper walls and update your ventilation.

 

[dann09]

Clean out all existing air bricks and install two more at the front wall.

The plates built-in to the solid walls are at risk of decay - they appear to be below the DPC hence at risk of rising and penetrating damp - only at risk, not certain that they are decayed.

Where the joists seem to meet the external walls they actually go into the wall say 4-6" to bear in a joist pocket in the brickwork. The bearing ends are at risk.

Chip away with your screwdriver and you will reveal the slate DPC in the sub-area and just above ground level outside.

You should have an access trap somewhere in the floor - perhaps under the stairs?

You must do a bit more research here and on google, esp ref pics of DPC's.

 

[joe-90]

If that floor were at risk of rot it would have rotted by now. Stop looking for faults that don't exist.

 

[tony1851]

Your floor appears OK. white/brown stuff on bricks will be salt deposits drawn up from the ground - nothing abnormal. White stains on timber probably stains left from mortar droppings during construction.
As others have said, check timbers which are just above dpc with screwdriver.
Insulation could be Kingspan boards fitted between joists tight up to u/side of floor boards. Support with nails driven into sides of joists. Shift any cables away from insulation.

 

[avangard]

Thanks everyone for responses. The floor looks to be in good condition to me too, just wanted to hear some second opinions as I'm by no mean an expert in this.

I'll do the 'screwdriver test' and clean up airbricks, as well as remove the organic debris when I will have more access.

Is it worth doint a preventative treatment on joists with some kind of fungicide or wood preserver is it just a waste of time & effort?

dann09, on which picture do you see the plates built-in to the solid walls that are below the DPC?
On the last picture I posted (http://i.imgur.com/3lCkzeN.jpg), it's quite clear that joists do not enter the brickwork, they just lie on top of another joist that sits on the slate DPC (is that what you call the wall plate). May be other joists do enter brickwork, not sure about that.

 

[joe-90]

Dan will ask a load of questions - but don't expect a meaningful answer.