Using info to build house

**Zetmandu** · 02-26-2011, 10:22 PM

Hi,
Well let me apologize first for the impending long explanation, but I think if I dont explain the whole thing it will be pretty useless to try and see if i can get what I need and thanks in advance.

Ok, so I am planning to build a log home out of timber cut off my own land and to do this of course means I will have different diameters of logs and this also means since logs taper over the course of the length of the log it will be bigger on one end that the other. So what I would like to do is make a work sheet with each log given a number and the number of the log will have the diameter of both the big end and the small end listed beside the number basically a format of log# in one column, big end size in next column and small end size in the 3rd column. What I am hoping somehow excel can do for me is to tell me which logs to lay in what order in each course, with a course being 4 logs laid out to make a square so that as I build upwards each course is as close as possible to the same distance from the foundation. Any ideas here?

**Palmetto** · 02-27-2011, 09:17 AM

A solution may be possible.
How close do the matches need to be? What is the tolerance?

As a quick start on getting comparisons, you might use a third column to combine the two end diameters into a single value, then sort to ascending or descending order.

Theoretically, two logs with the same combined diameters are a match.
So, if you order the list and take the logs in sets of four would that work for you?

**shg** · 02-27-2011, 10:19 AM

I am planning to build a log home out of timber cut off my own land

Wow! What fun!

... combine the two end diameters into a single value, then sort ...

Is that true, P? One log might be a cone, and the other a cylinder, both having the same combined diameters.

**Zetmandu** · 02-27-2011, 12:25 PM

Hi and thanks for the input.
The tolerances should be no more than 1/2" difference between any of the corners to the foundation and based on the fact that I plan to use logs no smaller than 12" diameter on the small end for an 8ft tall wall would need a minimum of 8 courses of logs.

**Palmetto** · 02-27-2011, 09:41 PM

Is that true, P? One log might be a cone, and the other a cylinder, both having the same combined diameters.

Yes - possible, but not necessarily probable given it is, likely, pine timber.

Truth be told, I kind of expected to take a hit on that suggestion which was, admittedly "shooting from the hip" based on a few assumptions.

1. Loblolly and Southern Yellow Pine (if that is what is to be used) is a reasonable uniform growth timber.

2. Candidate logs would be culled to remove extreme variations from the supply and only the most uniform logs used for construction
-------------------------------------------------

Zetmandu,

It is best to upload a sample workbook with some data.

**incjourn** · 02-28-2011, 10:34 AM

Just and idea....

Both these actions are important
- Sort by largest to smallest average diameter
- Sort by calculated difference between large and small diameters for each log.

The question is which sort to do first. One suggestion is to first sort by largest to smallest first and then divide into 3 or more categories of average diameter and then sort by difference between these categories. The way to tell if you've got enough sort groups is to calculate the greatest % difference any adjacent logs and see whether it is within acceptable limits.

Once you have the sorted lists you pick logs 1+3 then 2+4 laid in opposite directions.

I may be barking up the wrong tree of course (no pun intended).