Rotten Floor Joist. Help

shap101

Yesterday I noticed that the corner of my mums front room had dropped about an inch, I pulled up a couple of strips of laminate flooring and a floorboard.

The first joist  has rotted away and the one next to it looks like it's on its way out, I have reached under the board and  joist feels soft to the touch and damp . 

The issue is that my mum spent around £500 less than a year ago having the laminate flooring done. 

Is the only course of action to start pulling the laminate up ( thought of photographing / numbering in case I can put them back ), then the floorboards chasing it back until I can find unaffected wood? 

I also noticed that there was what looks like pieces of slate on the floor, is this the damp course? .

It's a drop of around 3ft from the flooring to the ground so if I remove another board I could get under to check /repair . 

My concern is that I could be opening a can of worms especially as she's thinking of moving possibly at the end of the year ( she has been talking Bout it for the last 5 years though). 
Any help would be much appreciated 

Grenage

Yup you're correct, the floor needs to come up.  You need to find where the water is coming in and get that sorted.

grumbler

shap101 said:

It's a drop of around 3ft from the flooring to the ground so if I remove another board I could get under to check /repair . 

Are you sure there is no a hatch anywhere in the house to get under the floor?

shap101

Thanks for the indepth advice.   

The house dates to the 1950s,  my mums lived there for 40 odd years.  
 Will get underneath the floor tommorow to see what's going on ,.

What is the best way to check if the wood will be strong enough to hold the bolts,  is it a simple case of pushing in with a screw driver?  

shaun_from_Africa

Is there a history of flooding in the area where the house is?
A gap of 3 feet from the floor to the ground seems like an awful lot to me (the last house I had that had wooden floors only had about an 8" space) and the large gap may well be in case the area gets flooded.

stuart45

Modern houses don't normally have a deep crawl space as the oversite needs to be higher than the external ground levels unless laid to fall to a drainage system. Older houses often had 3 or 4ft down to earth. Gave builders plenty of space to dump rubble when working in your house.

FreeBear

Mickey666 said: Also buy some DPC material to wrap around the end of the joist before inserting it into the wall 'socket', which might help to isolate it from any damp in the wall.

If there are sleeper walls close to the external wall, there shouldn't be any need to insert joists in to 'sockets' - If there are wall sockets, it may be a better idea to fit joist hangers (but still use the DPC material between any brick/metal & wood).

shap101

Just pulled up another board and went under... It looks as the end has rotted in the wall about 25cm then the weight has then cracked the joist   internally" at a 45% degree angle running downwards to around 100cm point under the floorboards ( from inside the joist hole)  .  
It  looks OK after that point and sound.  
The joist has a width of around 5cm so would I need 
5 coach bolts of 150mm plus washers 
150cm length of joist 
Some damp course material?  

RelievedSheff

shaun_from_Africa said:

Is there a history of flooding in the area where the house is?
A gap of 3 feet from the floor to the ground seems like an awful lot to me (the last house I had that had wooden floors only had about an 8" space) and the large gap may well be in case the area gets flooded.

Our last 1930's house had a huge void under the wooden floor, it ranged from about 3ft at the front of the house to about 6ft at the back of the house. We never got around too putting proper access into it to use it as storage as it was bone dry down there.

No flooding issues it was just how the house was built.

Our current new build has a tiny 150mm void beneath the concrete beam and block floor.

FreeBear

Any clues as to why the end of the joist has rotted ?

What is the state of the remaining joists in the area ?

Often, when one has started to rot, others will be following suit.

shap101

I've added some breeze blocks and a piece of wood running the lengthbbl under the joist to prop it to the correct level and cut off about a 25cm of joist.  

Would I get away with keeping the breeze blocks in place and just replacing the end 25m of the joist ( one side in the wall the other on top of the blocksv) .  
My concerns getting a long length of wood under the floor through a 40cm hole without pulling some more boards up.