Reinforing Notched Floor Joist

[big-all]

this new fangle internet gets the better of me l o l
when you get messeges from people you are unshure off i am a bit wary as the last one i accsepted[ not from here] was a supposede femail talking very dirty which is fine face to face l o l

try again then i will know its you

 

[Deluks]

Thank you I really appreciate it.

By the way what size pilot hole do you make for an M10 coach bolt and is there a special tool for making a square countersink for the bolt head???

The obvious answer here is 10mm (think about it!)

The tool you are after is called a chisel. I usually grab a smallish one for this type of thing, 6mm ish.
You can just leave the square bit sticking out though, it makes no difference in this application.

 

[awbcm]

My friend this isn’t rocket science. I put you on the Big-all due to hime being at the front of the queue when diplomacy was handed out, while was towards the rear.

As already stated no polite hole required, but as a general rule a rule of thumb a polite hole is 1/3 to a 1/4 of the finely size you need.

But in the case of coach bolts etc no polite hole is required.

M6 bolt 6mm dia hole
M8 bolt 8mm dia hole
M10 bolt 10mm dia hole
M12 bolt 12mm dia hole

Regarding the square shank again as already stated no special tool required. In soft wood, plywood, MDF or OSB there is no need to make a countersink at all the. The square shank will pull into the wood when you tighten the bolt. The idea of the square shank is to prevent the bolt from twisting or turning when being tighten, therefore if you made the countersink to large and thus defeating the object.

Washers; surly common sense says that a washer would be a good idea and for the size well

M6 bolt 6mm washer
M8 bolt 8mm washer
M10 bolt 10mm washer
M12 bolt 12mm washer

You can get washers called penny washers, these did have a overall dia the size of an old penny hence penny washer but know have an overall size of 25mm and are available with hole sizes suitable m5 – m12. I would recommend that you use m10 penny washers

In the case of coach bolts you only use a washer under the nut.

Regarding the notching

Let me ask you a question; Why are you repairing the joists have the joist under gone excessive notching ? And if so don’t re-notch the repair to deep even better drill.

This isn’t rocket science.

 

[zand108]

I do recognise that this isn't rocket science but honestly where is the sense in making assumptions & steaming ahead with what I THINK is a really good idea or dismissing what I THINK is definately a stupid idea when I can take 5mins to search on DIY forums and if that fails 1min to ask a question on forums from somebody that already knows the answer and so removes all doubt ???

Just because I can visualise how a DIY'er would go about doing something doesn't mean it is neccesarily the way that a professional would go about it. Just covering my bases is all.

I understand that answering questions that are obvious and simple can sometimes be incredibly annoying and that is why I really appreciate you and others taking the time to answer them even more .

Many thanks.

 

[awbcm]

I understand that answering questions that are obvious and simple can sometimes be incredibly annoying and that is why I really appreciate you and others taking the time to answer them even more .

Many thanks.

Yes some questions are incredibly annoying and in some case totally stupid and i have to step back and hope someone else will give a reply more diplomatically than my self.

A photo of the finished repair would be good so others can learn by comparing before and after. Yes ?

 

[zand108]

awbcm, you recommend drilling over renotching the joist. I realise that this is probably gonna be yet another simple question but...

If I drill I would use a 32mm drillbit, and would be drilling a hole through the centre line of the joist i.e. directly underneath the 2in notch I have just repaired.

Won't drilling a 32mm hole directly beneath a 2in notch further weaken the structure of the joist?

 

[zand108]

A photo of the finished repair would be good so others can learn by comparing before and after. Yes ?

Gladly!

 

[awbcm]

Just drill the OSB were the notch is, no need to drill the joist.

 

[big-all]

me personaly would go for a minimum of 7x1" each side overlapping 400 to 500 beyond the dammage with washers and dogs inbetween the timber faces
http://www.screwfix.com/prods/99094...alwork/Timber-Connector-50mm-x-M12-Pack-of-50

although in your case you wont get 7" uninterupted top edge!!

excluding the holes what is the maximum size off wood you can get in without needing to notch the top!!!

 

[zand108]

The maximum size of wood I can get in without any notching and ignoring the holes is 5". You can't see it in the picture but there is a 2" length of wood which runs at right angles to the base of the joist and the pipes sit in a 1" notch at the top of the joist.

 

[big-all]

The maximum size of wood I can get in without any notching and ignoring the holes is 5" you can't see it in the picture but there is a 2" length of wood which runs at right angles to the base of the joist. and the pipes sit in a 1" notch at the top of the joist.

just realised the pictures are from opposite sides off the joist

5 inches would be helpfull and probably give enough support iff attached to both sides!!

but could you rethread the wires /pipes through the same holes and through the side plates ok!!!

 

[zand108]

No, I tried to trace the ends of the wires but they go to far into/under other rooms.

There doesn't seem to be a way to get a single piece of wood into the gap without cutting it to accommodate the wires. Unless you know of a trick or two???

 

[big-all]

what centres are the joists at 16"!!!!!

what is immediatly supported above the weakend joist in the area before the previous and next joist!!!!

 

[zand108]

The joist centres are at 16 inches.

I am not exactly sure what you mean by

what is immediatly supported above the weakend joist in the area before the previous and next joist!!!!

Apart from people walking over them on their way to the bathroom. There is nothing currently being supported by the weakened joist or the previous and next joists. They start on the corridor and pass into an adjacent bedroom where the only thing above them there is a rug.

 

[big-all]

ok you have the weak joist and at 16" centres either side you have a normal joist
within the 32" strip that the weakend joist covers what off any weight is physicaly resting in that area [only include the bath if the feet are within this area]!!