Levelling Joists

[Mercuryrev]

First post, so please excuse any lack of info and my 'improving' DIY knowledge....

Restoring our upstairs bathroom in a 250 year old farmhouse in France and need to get the floor as level as possible. I am installing a shower tray in an alcove and had to replace two joists, which I levelled.

The remaining joists in that section of the room run down (from right to left) by 10mm from the outside wall to the centre of the room where they sit on a massive oak beam. Walls are mud and rubble and straw, but they are nearly a metre thick.

I am in the process of replacing the joists in an attempt to level the floor. The joists are approx 80mm x 60mm x 1250mm and made from douglas fir. They are spaced at 30cm centres. At the wall end the joists rest (for between 7-10cm) on what appears to be an incredible hard brick.

As I have a 10mm drop from the wall end to the centre of the room (the remaining floor drops very slightly into the centre too) is it acceptable to notch the bottom of the new joists by 10mm?

Thanks in advance.

 

[bernardgreen]

Assuming you are not breaking any local building regulations / conservation regulations the best option would be to add a bearer on top of the main beam. The bearer's thickness under each joist can be adjusted to get a level joist while the joist is in place. Notching the underside of the wall end would require accurate determination of the difference in height between beam and wall bearer, ( the size of the notch ) before the notch can be cut and the joist fitted.

Notching the under side of a beam is never a good idea as it weakens the beam far more than the same sized notch on the top surface.

 

[Mercuryrev]

Assuming you are not breaking any local building regulations / conservation regulations the best option would be to add a bearer on top of the main beam. The bearer's thickness under each joist can be adjusted to get a level joist while the joist is in place. Notching the underside of the wall end would require accurate determination error and the required of the size of the notch before the notch can be cut and the joist fitted.

Notching the under side of a beam is never a good idea as it weakens the beam far more than the same sized notch on the top surface.

Thanks very much for replying

I believe there are building regs in France, but as far as I can discover nobody bothers following them! French logic rules!

The beam end of the joist sits on a notch cut into the top of the beam in the centre of the room, so would a 10mm (or greater) timber packer under the joist be ok?

Thanks again

 

[bernardgreen]

I believe there are building regs in France, but as far as I can discover nobody bothers following them! French logic rules!

The French can be very lax, or they can be extremely difficult. Especially if the local mayor has any reason to dislike the house owner.

The beam end of the joist sits on a notch cut into the top of the beam in the centre of the room, so would a 10mm (or greater) timber packer under the joist be ok?

That has been done in my cottage some time in the past. Seems to work OK provided the packer cannot slide out of the notch.

 

[Mercuryrev]

[/QUOTE]The French can be very lax, or they can be extremely difficult. Especially if the local mayor has any reason to dislike the house owner.

A tin of M&S biscuits, going to the Remembrance service and helping clean the church seem to have helped in the Mayoral relations. After Brexit we may have to start sending flowers every week too!