Walls: create and calculate number of blocks or bricks?

[carlos.197751]

this is something different:

there are so many parameters within a single wall to define materials in layers of the wall. But within any material i haven´t found a way to solve this.

I have to make a wall wich in the real world is a compound of bricks or blocks. The material for that wall within revit haves only a pattern applied to the surface or a renderer look wich are both look like a brick wall.

When creating a material takeoff schedule, there is a way to obtain the area or volume of that wall. But there is not a way of obtaining the quantity of bricks needed ...?... ie. if the brick size is 20x20x15 mm ?? ...

[sfaust]

make a calculated value that is "area of wall/area of a single brick". That won't get you exact because of waste/scrap, but darn close...

[patricks]

I would probably calculate the value using either area of wall divided by area of a single block, or volume of wall divided by volume of single block, then have it multiply times 1.1 (additional 10% for waste), and then add 0.49 to it. Create another value set to integer (instead of number), and set that equal to your first calculated value. That will give you an approximate block number with waste taken into account.

Now if you don't want to take waste into account (let the contractor handle that), then skip the 1.1 multiplier. Just add 0.49 and have the 2nd integer value.

If you do have that multiplier for waste, then you should probably put a big note saying that waste has been taking into account so that the contractor bidding on the job doesn't add his own 10% or whatever amount for waste, which will give you an inflated price.

[twiceroadsfool]

Short answer: Calculated value, as sfaust and patrick have indicated.

Long answer:

Getting in to the nuts and bolts of whats possible with the Revit model, this is the point in the project lifespan where i would suggest sitting down with the project team and discussing quantity take offs, what youre using them for, and how/why youre calculating them.

Is it for pricing? If so, i would get with the contractors/estimators and see how THEY are pricing the wall, in terms of area, volume, linear dimension, or "by brick." If its a line item that they are figuring based on linear feet of brick they have to lay, and heignht of the wall, that they then mutiply by a "cost per hour per linear foot (or area)" then having the exact number of bricks wont mean a thing.

Plus, it IS going to have a decent amount of error in it. First, when it calculates totals, it will add up all the little incindiary 9sp?) bits and fractions of brick together to form whole bricks in the total, which they wont do in the field, so you will be short. Plus at openings, it may calculate different than how the masons lay the brick/block, and FWIW, they may not lay every single brick in a run perfectly, and over 50 feet they may need a lot of extras, or be a little heavy.

I know you know all this, but the point im making is: Is the exact count of bricks really going to help? If it is, use the calculated value method (heck, you cna even calculate mortar and brick ties that way if you like...). But i would question the validity of such a number...

If youre really not happy with that solution, model the entire brick wall out of a curtain system, and watch how quickly Revit can turn a sane man crazy, and a blazing piece of hardware in to a windows ME-esque lumbering piece of paperweight. :)

[patricks]

I figured the 10% multiplier should cover waste, cutting bricks/blocks at openings, corners, etc. Not sure if 10% is correct or not. I'm sure there is a certain rule of thumb most all estimators use for block and brick when estimating.

[clinton.204555]

make a calculated value that is "area of wall/area of a single brick". That won't get you exact because of waste/scrap, but darn close...


Hi there I am from South Africa and I can't seem to get this to work, could you perhaps explain to me how to go about doing this? When I put in a formula it does not work.

[ejburrell67787]

We would only ever calculate brick areas as a metre square quantity and I would agree with patrick that 10% on top of this should cover cuts around openings etc. Contractors and supplier we work with use either a square metre of bricks or a set quantity of bricks (ie cost per 100).

Clinton: In terms of the formula, set up the material take off schedule and open the view properties dialogue box, select the fields button/tab and hit the calculated value button. Provided you get the units correct and the parameter names correct (including spelling, upper/lower case, spaces etc) then the formula should work fine. Note: if you are dividing the schedule wall area by the area of a brick that you have worked out (ie brick size plus mortar above and to one side, which in the UK is 225mm x 75mm = 0.169m2) there is no way to make the number you are dividing by as an area unless you build it into the schedule as a separate parameter and so the answer will also need to be an area. (Units: area / number = area, as opposed to area / area = number if you make an area paramater to divide by) Unfortunately this will give a result with a m2 unit, however, you can hide this under the formatting tab Feild Format button. (uncheck project settings and chang the unit symbol)

I've attached some screen shots, hope they help.

Hope this makes sense!