Those missing Part A span tables

[downshifter]

Trying to calculate the size of timbers needed for joists and rafters etc. It turns out the span tables used to be in the building regs part A up til 1991 but have since been taken out. Now you have to buy them through TRADA for £30 or so. Outrageous why should we pay for what was free information.
But a bit of tinterweb searching and huzzah they can be found here http://www.planningportal.gov.uk/uploads/br/BR_PDF_AD_A_1992.pdf
Great resource if anyone needs this
But does anyone know if they have been superceded or does the old values still apply?

 

[stephenh]

Thanks for that - very handy.

I have just compared the tables with my 1972 (!) regs and they are fairly comparable, except that timber grading ( SC3 & 4 etc.) wasn't apparent so long ago.

Out of interest I was taught the following a long time ago by a site carpenter of some age:

To calculate floor joists.

Take the span in feet e.g. 10'
Halve it (5) and add 2 = 7 and this is the depth in inches.
This would be a 2" (50mm) wide timber and would be placed at 16" (400mm) intervals.

Quicker , cheaper and easier than asking an SE or looking it up.

It made for slightly heavier floors, a more robust build and one I still use occasionaly.

 

[benmc]

I have a pdf of the latest tables if anyone needs them.

Ben

 

[Penners]

I was taught the following a long time ago by a site carpenter of some age.....

And I'm sure that old boy's rule-of-thumb worked entirely satisfactorily. The trouble is that it's unlikely to satisfy a BCO, when submitted as part of a Building Regs application.

In days of yore there were no calculations for housebuilders to work from. They just guessed what would do the job, then added a sizeable amount of extra mass in case of error.

The result? Houses that have lasted half a millennium or more.

 

[Penners]

Outrageous why should we pay for what was free information.

You could say the same about newspaper web content - particularly The Times. Their website used to be free, but now has to be paid for.

The span tables undoubtedly cost money to prepare and to administer. And they're a commodity that has a ready and constant market. In a free market economy, I'm afraid that anything satisfying those criteria is likely to cost money, sooner or later.

 

[AMc]

My BCO was a chippie - despite having all the structural engineers calculations made up and cleared for our replacement vinery when he turned up he declined to measure anything - "If it looks right then it probably is right" was his comment!

Despite "they don't build them like they used to" comments the floor in the oldest parts of my house spring quite a bit and the joists are not that substantial, in the bits renovated to 2006 regs they're rock solid.

 

[MdB]

Despite "they don't build them like they used to" comments the floor in the oldest parts of my house spring quite a bit and the joists are not that substantial, in the bits renovated to 2006 regs they're rock solid.

I've doubled up all of our floor joists and there is still more flex than I would like.

 

[JohnB]

Take the span in feet e.g. 10'
Halve it (5) and add 2 = 7 and this is the depth in inches.
This would be a 2" (50mm) wide timber and would be placed at 16" (400mm) intervals.

I was told that, but nothing was said about spacing, when a builder looked at my only original ceiling. It explains why the floor bounces :roll:.

My neighbour reckons there may have been a supporting beam across the middle, but I won't know until I take the plaster off. As the ceiling height is 6'6", and I'm 6'2", there's no room to put a beam back and avoid brain damage :?.

 

[AMc]

Despite "they don't build them like they used to" comments the floor in the oldest parts of my house spring quite a bit and the joists are not that substantial, in the bits renovated to 2006 regs they're rock solid.

I've doubled up all of our floor joists and there is still more flex than I would like.

I also doubled up some of the original joists in the back of the house when we had them exposed - the chippie thought I was crazy for not simply replacing them with something sturdier and seemed surprised that the fact they were older than me, him and my dad combined was reason enough not to put them in a skip.
They certainly needed to be upgraded when we added a 5'8" cast iron bath into the room above though