Wood Wall Plate or Concrete Wall Plate

[SFK]

Dear All,
In my 1900's house, I have three Joists (2" by 7") that support the hallway floor. The ends of the Joists sit on a wood wall plate that is directly below the font door.

At some point there has been water ingress at the door. The end of one of the Joists is now rotten, and so is the section of the wall plate that the joist sits on. This has caused Joist to drop 1".

I believe the rot is/was Wet Rot. The area is now dry as water ingress looks like it has been stopped many years ago by previous owner with fitting of new door and air bricks.

To remove the rot I will cut back the Joist to 1meter from the rot, and splice on a length of new treated Joist (45mm by 200mm) using metal splice plates. This new section of Joist will fit into the original joist hole in wall and lie on the Wall Plate as before.

Regarding the Rot in the Wall Plate, my plan is to remove its entire length (900mm) from under all three Joists (which have no load on them as they only support the hallway floor).

My Question is regarding this wall plate on which the Joists sit:
a) should I replace it with a Wall plate made from treated wood, or
b) can I use a 900mm long concrete lintel as Wall Plate (This is my preference as I have an unused concrete lintel so there is no financial cost and my thinking being that using concrete is better than wood in case of any future damp or any remaining spores).

With many thanks, SFK









The end of one of teh Joists One of the Joists

 

[dann09]

What you propose sounds fine:

1. first prop up the joists, a little back from the work space:


2. Then, why not remove small sections of rotted cill and one joist tail at a time?

2. Hopefully, once released, you can wedge up and raise the joists to level. However, be cautious of distorting the door cill or threshold. Note that a level floor might pinch the door swing.

3. Once clear of fungal damaged wood, you might chemically treat the exposed area and then brick up to the pockets.

4. Allow the mortar to set and splice or bolt on the new capped joistings.

5. Or use your lintel instead of the bricking up.

6. Clear all debris from the sub-area.

7. Good ventilation is required under the cill.

 

[SFK]

Dear Dan9
With thanks for the suggestions. I undertook all the work this weekend including using concrete lintel as wall plate, splicing in new beams and putting in more air bricks.

I found that the wood Wall Plate was on a single wall with the room on one side and the porch on the other. As it was a single wall the Wall Plate and the ends of the three beams were directly in contact with the damp soil used to make the floor of the porch. The image shows the rot on the removed wall Plate and beams.


So I removed the concrete slab, original tiles and soil from the Porch. A new 'outerwall' and dpm put in to separate the porch area from the ends of the beams. The porch area will be capped with concrete slab and I will see if can use the original tiles that I found.

With thanks again, SFK

Wall Plate Rot

• SFK
• 4 Feb 2013
• 1

Wall plate and ends of Three beams in contact with Soil as no outer wall in Porch.

 

[noseall]

I undertook all the work this weekend including using concrete lintel as wall plate, splicing in new beams and putting in more air bricks.

Have you put floor joists directly onto a pcc concrete lintel?

 

[SFK]

No, wood joists are straight onto the concrete lintel. concrete lintel has DPC underneath it.

What should I have done?


SFK