Advice from Architects

[Matt Sugden]

Hi, I'm currently drawing up some plans for a planning application, and it has occurred to me that when I finally come to build these houses, the brick work needs to be neat, as in whole and half bricks with not too many cuts. Using a simple stretcher bond.

 

Is there a rule of thumb, or a good online resource which can help me calculate where to precisely place window and door openings, taking into account the running course of the bricks.

 

At the moment I am going through my plans and trying to calculate the wall lengths based on the brick length 215mm plus the mortar 10mm and putting the openings in places where they intercept in units of one (225mm) or a half brick (112.5mm) long, but this seems extremely laborious and a bit of a head frazzler. Especially when you start removing the mortar allowance (10mm) for the brick ends and corners where it isn't needed.

 

Is there any easier way?

 

Ta.

[YOHKOH]

Hi fella

 

You need a bricktable

 

Check out ibstcok

 

http://www.ibstock.com/pdfs/technical-support/TIS-09-Brickwork-dimensions-tables.pdf

[James]

The link from hopper452 is exactly what you're after.

 

I've tried for AGES in places I've worked to get staff to do this from the outset... glad to see at least one other person is adopting brick dimensions at Planning stage!

 

In short, all of your dims end up as multiples of 112.5, with 10mm added or subtracted depending on whether the dim is an 'opening' or a 'pier' respectively.

 

How do you identify if its an opening or a pier? Look at the two points of brickwork you're dimensioning between... each point will either be forming an EXTERNAL corner or an INTERNAL corner, so you're faced with three possibilities...

 

1. EXTERNAL corner to EXTERNAL corner = PIER (multiple of 112.5 -10mm)

2. INTERNAL corner to INTERNAL corner = OPENING (multiple of 112.5 +10mm)

3. EXTERNAL corner to INTERNAL corner (or vice versa) = CO-ORDINATING DIMENSION (always a multiple of 112.5)

 

Apologies if this isn't clear... its easier to explain with quick sketches

[AJLynn]

Ha! Another example of why everybody should be working in Imperial!

[cdos00]

Actually I believe this isn't just held to "bricks" This comes back to the basic question

 

"what unit are you using to build with"

 

When I use the term unit, I am not speaking of a unit of measure...but a unit of "being"

for example:

the reason our modern wheel-to-wheel width on cars is the size it is, is because it fit into the grooves a wagon made...the wagon was the width it was because it is the comfortable width of two horses running together...

 

So, before you draw anything, before you dimension anything...you should know what your "unit" is.

 

to use an example of "units" in the building industry, I bring up the traditional japanese tatami mat that was the basis for japanese architecture for so many years.

 

It poses a little bit of a "chicken and egg" question, but whenever possible you should have knowledge of the building materials ASAP.

[AJLynn]

Don't they still use that as the unit for living area? Like when they give the size of an apartment for rent? And you see it all the time in contemporary architecture - not the actual mat but its size being used as the module.

 

We got screwed big time on a project I worked on a while back where the PM had a lot of faith in a draftsman who's an idiot and thinks he's an architect. PM tells the guy to make sure everything is on CMU module. The guy doesn't and tells the PM he did. Weeks later I go to dimension the views and nothing's on module, meanwhile the engineers have already done a bunch of work. Everybody fights for a couple of days, fixes happen where they can and a whole lot of CMU end up getting cut.

[Matt Sugden]

Thanks for the great responses. i think i follow,

 

So essentially my window openings will be multiple of 112.5mm x Y + 10mm

And my surrounding walls will be multiple of 112.5 x Y - 10mm ?

 

I was slightly thrown by the extra 10mm on the window openings, but looking at the Ibstock drawing it makes sense... sorta.

 

Cheers

[AJLynn]

It's cause there's an extra mortar joint at the end. I recommend doing some 2d drawings of example conditions - with all the bricks at the real dimensions with mortar joint, it's not going to take long with Array - it's the only way to really understad what's going on.

[Frosty]

We got screwed big time on a project I worked on a while back where the PM had a lot of faith in a draftsman who's an idiot and thinks he's an architect. PM tells the guy to make sure everything is on CMU module. The guy doesn't and tells the PM he did. Weeks later I go to dimension the views and nothing's on module, meanwhile the engineers have already done a bunch of work. Everybody fights for a couple of days, fixes happen where they can and a whole lot of CMU end up getting cut.

 

AJ, we had a similar situation a few years ago....from a "high end design consultant". They knew it was CMU construction and placed windows/doors wherever at whatever sizes. To make it even more fun, they didn't snap corners or draw lines at 90 degree angles. They might as well have given us a napkin sketch! Every single line in the plans, sections and elevations had to be redrawn.

[aaron-cds]

You're over thinking this. It's simple, create dimension strings that say the following +/- 10'-8" (16 bricks)

 

If you use the nominal brick length for the dimension and tell the builder how many full bricks to use, it's pretty clear that you don't want to be cutting a ton of bricks. As for the whole wall, you're going to find that your carefully measured system goes out the window when the guy pouring the foundation builds the wall an inch or two shorter or longer than your dimensions due to a common thing refered to as construction tollerence.