Distance between posts for 5 x 3 posts and 6ft featheredge

[the carpet man]

Whats the normal distance between posts using 5 x 3 posts and using 5 inch wide x 6ft featheredge, and 3 arris rails ??

[Chris Bacon]

3m maximum. Are you putting up a fence, or just asking? At this length you ought to make sure that your rails are of good quality, no large knots (especially near the middle of the length), etc. Measure up and see what distances "work". Consider fixing the boards in alternate bays in different directions for reduced look-through.

[the carpet man]

Ive got 20 ft ( 6 m ) of fence to put up, but thought that 3m was too much (using 3 posts), but then again I thought 2m (using 4 posts) was too close.

I prefer the 3m as its going to be quicker and cheaper.

Quality of products (ie knots) is always a problem, as there is no good timber around.

Thanks