Fitting Floor Joists Extension

Floor joists installed on second or third or higher levels double as ceiling joists for the level below.

Fitting floor joists extension.

From what i can guess this doesn t seem like enough space to try and fit an 8 joist into. How to replace rotten floor joists and insulate a suspended wooden floor in 1930s house by jon april 27 2018 ok so in august last year i moved into a 1930s bungalow it s a lovely little home with a just 2 bedrooms and a boxroom a front room dining room and small kitchen. The builder inserted the air bricks and dpc too high which meant that when he put in the floor joists hung off ledger boards bolted directly to the blockwork the ledger boards covered the air bricks and all the timbers were below the dpc. New floor joists are measured and trimmed to size then dropped into the joist hangers and secured in position.

This size is no longer acceptable when framing a structure. Spacer noggins solid struts are installed between joists to reduce joist deflection vibration improve floor rigidity and performance. The reason was the corners of the new joist when at a 45 degree angle caught the top of the beam and the bottom of the floor boards. In buildings with basements the first level of floor joists serves the same purpose.

In the past 2x4s or 2x6s were sometimes used as floor joists. Once the joist was vertical it would fit fine hence the slight floor jacking. Ceiling joists are tied to the floor joists with steel straps to stabilise the ceiling. Regardless you should check and confirm new floor joist size with your local building control authority before proceeding.

What i am after is something like a reverse joist hanger. If i cut the joist to fit that gap i believe i simply wouldn t have enough material in play to resist shearing stresses. Lay out your joists so that they will be spaced 40 cm 16 inches on centre. I m having a single storey extension built approx 4m x 5 8m.

Decide whether you wish to set the joists so that they run over a beam butt together over the beam or fit them into hangers attached to the sides of the beams. The new joist fit in the space sideways but would not tilt into vertical position.