PDA

View Full Version : Problem with height of piers - notch out joists to compensate















wombarrapete
23rd June 2005, 09:49 PM
G'day all - I've got a bit of a dilemma (and a possible solution) which I was hoping to get some comment on ..

First of all a little bit of background .. I'm building a 10*6mtr deck which will join up with the existing deck that runs down the side of the house to form a big L.

The plan was for it all to be the same height ... read on ..

1. Dilemma - brickie has finished some work while I was away .. got back and have found that all the piers are 20mm to high...so the new deck would butt up and be 20mm too high ...bummer.

2. Solution ... I was thinking about what the hell I was gonna do now when I came up with what I thought was an ingenious idea ... can I just notch out the joists 20mm where they meet the bearers !!

The bearers and joists are all 140x45 treated so I'd be losing about 15% of the joist in that little notch out so my only concern was would this weaken the structure ?

I didn't think so but was hoping for some more experienced views on this or some other ingenious solutions...

cheers
wp

ozwinner
23rd June 2005, 10:35 PM
My solution.

Get the brickie back to redo the last course.
Even if you have to repay him to fix it, it will work out better in the long run.

Al :)

journeyman Mick
23rd June 2005, 10:40 PM
welcome aboard Pete,
here's my answers in order of preference:

1)don't pay brickie till work is rectified (assuming that you instructed him on the finished height of piers), you didn't pay him yet did you? If you did then you could:

2)shoot some new levels on the piers using a dumpy level and cut off the offending excess with a 9" diamond blade (very dusty, but as bricks are relatively soft it won't take too long)

3)check the span tables in the appropriate framing manuals to see if the joists and or bearers can be reduced in height (maybe 10 mm off each)

4)check with an engineer to see if you can check the bearers out over the piers as you describe.

1 is definitely the best option, but it may prove near impossible to attain. 2 would probably be less painful than 1 and a lot less mucking around than 3 and cheaper than 4.

Mick

wombarrapete
23rd June 2005, 11:08 PM
thanks fellas .. that's exactly the type of advice I was after .. brickie is a mate of a mate and a good bloke .. I'll get him back in and we'll work out something along the lines of 'arolds & point 2 of Micks advice.

btw..some good news ..I've just been out remeasuring and it's not all the piers, out of 20 odd piers it looks like only a few are out.

thanks for the help

wp

bitingmidge
23rd June 2005, 11:38 PM
btw..some good news ..I've just been out remeasuring and it's not all the piers, out of 20 odd piers it looks like only a few are out.
Sorry about bagging a mate, but he isn't much of a brickie!
:eek: :eek:

At least it should be easy to work something out; but do try to get them all level before you go further!

cheers,

P ;)

silentC
24th June 2005, 09:12 AM
My first thought was Mick's number 3. If you don't already have all the stuff on site that is. You can often go up a grade for a smaller size. If it was me, I'd go that way because it means you don't have to touch the piers and there's nothing worse than having to redo existing work. I reckon, anyway...

ozwinner
24th June 2005, 09:24 AM
Sorry about bagging a mate, but he isn't much of a brickie!
:eek: :eek:

At least it should be easy to work something out; but do try to get them all level before you go further!

cheers,

P ;)I thought the same.
When I do piers I either set them with the laser, or with a string line, either way I always set them down a couple of mm.
Its always easier for the chippie to pack up the bearer than go cutting bits off.

I know, its not easy being perfect like me.:rolleyes:

Al :D

ian
24th June 2005, 09:31 PM
Dilemma - brickie has finished some work while I was away .. got back and have found that all the piers are 20mm to high...so the new deck would butt up and be 20mm too high ...bummer.

2. Solution ... I was thinking about what the hell I was gonna do now when I came up with what I thought was an ingenious idea ... can I just notch out the joists 20mm where they meet the bearers !!

There shouldn't be a problem notching out the joists. Span tables are about limitations on bending, what you are worried about is shear. (sorry to get a bit technical) I'm not up on current codes, but you can usually remove 1/3 of a joist's depth over a support without any problems. I think fire codes require that timber joists butting into part walls have 1/2 the depth removed so in a fire they fall out of teh wall rather than bend teh wall.

ian

julianx
24th June 2005, 11:03 PM
There shouldn't be a problem notching out the joists. Span tables are about limitations on bending, what you are worried about is shear. (sorry to get a bit technical) I'm not up on current codes, but you can usually remove 1/3 of a joist's depth over a support without any problems. I think fire codes require that timber joists butting into part walls have 1/2 the depth removed so in a fire they fall out of teh wall rather than bend teh wall.

ian
This has always been my understanding as well, although you need to wiegh up the amount of work would be involved in each solution. My first choice would be to get the brickie back to level them, if you don't start with a level base you'll be compensating all the way through job

soundman
25th June 2005, 09:42 PM
If you havn't already, get a dumpy level on the site and mark up everything verticle with a reference line. If its verticle & isn't mooving mark a reference on it if its mooving stop it then mark a reference line on it.
It will tell you the truth to within a sharp pencil line.
If you set your deck out with a dumpy it WILL be level.
cheers

ozwinner
26th June 2005, 07:35 PM
If you set your deck out with a dumpy it WILL be level.
cheers
Just as long as you dont get the brickie to look down the dumpy, otherwise he'd tell you eveything is hunkydory.

Al :D

Pulse
27th June 2005, 04:31 PM
Pack up the old deck? 20 mm over a few m is not much. Tough if it is attached to the house.....