HELP!! Water Damaged Joists

[oppa]

Hi,

Hope to get some advice on the following as this is my first time facing the situation.

I’ve moved to a new house and started work on the 1st floor bathroom, only to find the floor is water damaged. Water has escaped through the bath seal and tiles and rotted the floorboards and surface of two joists. I’ve uploaded some photos of the damaged joists. You can access them if you copy paste the below link or click on it. Two damaged joists are marked 1 and 2.

https://drive.google.com/drive/folders/1ZsmOhKuAaOAP1NRSB1DSksY40Ib9pnhf?usp=drive_link

I’ve removed the rotted area using a multi tool, and the remaining wood shown in the photos is solid. The affected area in each joist is about 30 cm wide and 10-20 mm deep. The joist are 8 * 3 (200 x 75 mm) inches.

What’s the solution for this? Do I need the service of Structural Engineer or can a Builder/Joiner fix this? I am more concerned about fulfilling the building regulations and protecting myself from any obligations I have when selling off the property in the future. So I’d like to get the service of professionals rather than DIY.

Thanks.

 

[Wayners]

I used to lash on clear wood primer and preserver.
Then screw or bolt through timber to the side of damaged joists.
If joist has sagged I have propped up.
When done you can jump up and down on repaird joist.

Looks fine to me. Add timber where necessary

 

[JohnD]

Use a wire brush, it will remove any weakened material. After that, drench with a spirit-based wood preserver (not a fence stain).

The joists are quite large. What is their maximum span between supporting joists?

 

[oppa]

Use a wire brush, it will remove any weakened material. After that, drench with a spirit-based wood preserver (not a fence stain).

The joists are quite large. What is their maximum span between supporting joists?

Thanks. The joists run left to right of the property and supported on the the two walls. Joist Spacing is 400 mm and clear span is around 4.5m. The damage is about 2 m from the the closest supporting wall.

I used to lash on clear wood primer and preserver.
Then screw or bolt through timber to the side of damaged joists.
If joist has sagged I have propped up.
When done you can jump up and down on repaird joist.

Looks fine to me. Add timber where necessary

Do I need to hire a builder to do this and a structural engineer to calculate the timber, screw size size etc?

 

[Wayners]

Nope. Just get on with it yourself.
It's just a floor joist.
You don't need to calculate the weight bearing and span.
Worst case if it was rotten at wall hanging points it to replace the joist.