What timber is this /question re joist

[Francis Tan]

Hi, we recently bought a house in Burwood, Sydney that was built in the early 1920s. It currently has carpet on the floor which is at least 20 years old and we are thinking of ripping out and polish the floor board. Looking at the subfloor are you able to tell me what type of timber is the floor?

The picture was taken by the building inspector and unfortunately doesn't have the best resolution and is the only picture of the subfloor but I was hoping that this picture plus locality may give some clue to the type of timber.

58648

Second question is re the joist which we were told has previous termite damage (no longer an issue) and therefore needs replacing. Can anyone tell me if the floorboards need to be lifted in order to replace this, or can it be replaced from the sub floor? Would you replace this before sanding the floor?

Many thanks in advance.
Francis

[davo453]

Hi Francis

I'd say it's impossible to tell the type of timber from that photo. But If someone lives in the area they maybe able to take an educated guess at it I suppose.

Replacing a joist from below would be a real hassle and obviously impossible if there happens to be a limited crawl space.

I'd lift the boards. You never do know what extra damage the termites might have done.

Cheers

Dave

[brynk]

gday francis

as mentioned by davo453 replacing a joist can be a real <...>! here is another option for you to consider

you need to instal two additional members that will hang from at least one sound joist (but two would be better) on either side of the damaged one within say, 300mm either side of the damage. then on top of these two you rest a new joist running adjacent to the damaged one. maybe a picture will help...

in that piccy you can see the joists are dark red. the damage is bright red. the two new hanging beams run across (transverse to) the direction of the existing joists at 90 degrees (dark blue). they hang from the existing joists and are fixed off by 50x50x6mm piece of equal angle (light blue), with 2x m10 bolt or coach-screw into each joist & beam attachment. be sure to have at least 100mm overhang after the angle at each end of the hanging beams

your new members should be f17 seasoned hardwood 90x45 or f14 unseasoned hardwood 100x50. if you use the 90x45 you will need some packers to go under your new joist where it rests on the hanging beams - these should be steel, fc-sheet or hard plastic; if that is a bearer that i see in the photo then you can take out one of the hanging beams, & rest on that instead - be sure to get as much of the new joist onto the bearer as possible.

you might also wish to fix the remainder of the damaged joist to the new one running along side it with nails or screws in the areas where it is sound.

r's brynk

[Francis Tan]

Thanks, that is really useful. If I were to get a carpenter to do it (as you can see I am clueless on this:U) how much do you think it will cost?

Also, if the floorboards are lifted to fix this, how likely is it that they can be reused?

cheers,
Francis

[Tools]

If you lift the boards you ar elikely to damage some and need to find matching replacements.Seeing as you want to polish the floor, I would do it from underneath if you have the room.

Tools