Replacing floor joists

[Andrew in Tas]

Hi

I am currently in the process of putting a new floor through the kitchen and bathroom. The existing floor is pine and in is poor condition. I intend to replace it with Tas oak. The old floor creaked and squeeked somthing shocking. After lifting the boards I discovered that while most of the floor joists are 6 x 2 there are five which are about 130mm wide (they span a smaller distance). These joists have been packed up with strips of timber and/or masonite to the height of the 6 x 2's. I suspect the packing may have contributed to the creaking. The floor is on the second storey and the downstairs ceiling is nailed to the joists so replacing them is out of the question. I intend putting in some new joists beside the five old ones, removing the packing on the existing ones and just nailing the new floor to the new joists so the old ones are no longer in contact with the floorboards. I am thinking of using green 6 x 2's. If I get the floor nice and level am I likely to have any problems as the new timber dries out? Also what is the current thoughts on laying floorboards in place for a couple of weeks before nailing them down. I have heard opinions for and against. Thanks in advance

[journeyman Mick]

Andrew,
it's generally accepted "best practice" to acclimatise your flooring by stacking it in the room where it will be laid. Shrinkage rates vary from species to species and depending on what the MC is when it is laid and also the grain orientation of individual members. Anything from 3 - 10% is possible. 10% of 150mm is 15mm, can you live with a 15mm bump in the floor? Best to use kiln dried hardwood or perhaps to replace the packers with solid blocking and/or steel brackets and bolts.

Mick

[Andrew in Tas]

Thanks Mick,
as usual you advice makes good sense, I'll going to make myself repeat a thousand times "I must not be a cheapskate".

I'm trying to picture what you mean as far as using brackets and bolts, do you mean screwing right angle brackets to the sides of the joists and then bolting timber to the top of the bracket? If so what size brackets and timber would you recommend and what spacing for the brackets? Or am I on the wrong track?

Thanls again

[gnu52]

Hello Andrew, what Mick says is good advice, steer away from green stock.

Another approach that may suit , assuming the packers are on top of the joist, & dont laugh I have seen the packers on the ceiling side, is to glue solid packers on top of the existing joists. Cut them to width & several mm proud.
Clean the joists until clean wood shows to get the glue bond right, predrill every 300 or so and pull down the strip with batten screws fitted with washers. When the glue is cured, remove the screws and set a string line on nails into the outside joists using your sliding square to set the height. ie string will be 25mm above the joists.
With this as a guide , & moving the string along the joist as needed plane/sand the packers to the correct height. Countersink & replace the screws. The joist line should finish solid and level.
You can dry fit the packers if preferred, but I would use construction grade adhesive to lessen the chance of any movement. I would use screws rather than nails because they pull down better and the hammering may not be kind to your ceiling.
I would use those smiley faces here and there but the kids are'nt here to show me how, showing my age hey.
Good luck with your project, Bill

[seriph1]

all sounds like good advice to me ..... I add my 2 cents worth in saying "as far as you can, limit any impact on that ceiling below"...... I feel this will just compound the problems. Thinking along the principle that laminated is stronger than a single piece of material, it might pay to coach-screw (or similar) and glue (epoxy preferrably) strips to the top of the existing joist as well as placing vertical members beside them ..... doing this means all you will require is fairly standard materials which will keep the costs at bay .... in fact why not rip the tongue off, use the old pine flooring as it would still be strong when placed on its side (rigid strength) and once married into the existing joist+fill piece will result in a good nailing surface for your next floor - which I also recommend nailing with a nail gun to minimise impact on that celing. And if you really want to minimise bounce you can marry in a piece of flooring on either side of all the joists.... add epoxy & 40mm screws to hold it all in place while the epoxy goes off and away you go!

.... or am I so far off the beam (nyuk nyuk) that it isnt funny?

[echnidna]

I would go for your original idea of extra joists - but using seasoned timber
Not fixed in any way to the old joists.
Fix them so they sit at least 12mm above the top of the old joists.
this way the downstairs ceiling is not attached to the upstairs floor and sound transference will be minimised if not totally eliminated.

[Andrew in Tas]

Thanks for the advice guys. It took a while but I've just worked out how to put the smiley faces in Bill. When you type the message you will see in the group of icons above the text box there is a smiley face. Click on the arrow beside it and then click on the face you want.

Andrew (the new found computer guru)

[seriph1]

oh turbin-wearing-one ..... by the way, what span are we talking?

[Andrew in Tas]

Steve,


The kitchen and bathroom encompass an area of about 6.5 metres by 3 metres (Its an unusual layout with the bathroom next to the kitchen). The joists span 3 metres in the bathroom and part of the kitchen. In the rest of the kitchen, where the problem joists are, the joists are sitting on a masonary wall which divides two rooms downstairs, so the span is only about 1.5m on either side.
I say "the problem joists", after running a straight edge over the floor I think they all now fall into that category arrggh (just because I know how!)

[seriph1]

lol- only a minor concern...... can you produce any pics via digital camera? If you can, yet dont know how to resize them for here, send them to me and I will resize them for you ..... am dieing to see the project and the home - sounds great

[Andrew in Tas]

G'day Steve,

I'm still using an old 35mm camera at the moment but a digital is on the shortly to buy list. I haven't even got a scanner.

Andrew (the not very well equipped new found computer guru)

[seriph1]

totally understand ..... while I no longer use my old banger 35mm (old $5000 semi-pro banger .....sorta like any PC bought yesterday) I can relate to the days when it was all I had. If you look on eBay you will find squillions of digital cameras for very reasonable prices.

But to more pressing issues - do i read correctly that the span each joist has to cover is 1500mm? If so, this is great news because you should have great success with the methods described above. The uneven-ness of the joists is of course another matter, though you would appreciate that all building is simply using timber, steel and other materials in the art of disguise. You will be able to get the floor looking right by deciding on your starting point and running string lines along to keep everything basically aligned ..... I am thinking yours might be an older place, so it may be less important to have absolutely perfect levels..... would love to see the job and the place if its real old.

have fun!

[Andrew in Tas]

Yep the span is only 1500. There are a lot of very nice old colonial buildings is Tassie Steve but I'm afraid mine isn't one of them. Early 1950's made out of the old solid 18 inch x 6 inch x 3 inch concrete blocks and steel framed windows . The good news is its in quite a nice area on the side of a hill with good views to the Derwent Boy I'm giving these faces a flogging now!

[seriph1]

gotcha - think they might be called Besser Blocks - is your place in a street of those or is it full of Aust. Colonials? I just can't get enough of them!

SWMBO and I must trundle down to the island one of these days ..... I still remember the beautiful homes and Salamanca, of course.

[Andrew in Tas]

Hi Steve
What I know as Besser blocks are not as long as mine, and they are higher and hollow. I'm not sure who made these, could have been Besser I guess. There dont seem to be many houses around made of these types of blocks. This house was built in 1954 and is one of the earliest in the street. Most look to be 60's, 70's and 80's. They are a mixture of brick and weatherboard houses.

If you haven't been down in a while you'd notice a change around the Salamanca/waterfront area. There has been a fair bit of development (most of which has been good) and the waterfront is the real hub of the city