Monday, May 28, 2007

Laying Pavers

I've been stealing a little time here and there - 4 hours at a time - to place pavers in my landscaping project that has been going on for... ages. I've been working with dry fit masonry for over 5 years now, strictly as time permits. Mostly, dry fit (my term I think - and as opposed to what I would guess is wet fit which would involve mortar) is easy stuff. You stack blocks to make little retaining walls and there you go.

Well, my project features a 4 ft high serpentine retaining wall, a 3/4 circle planter and 5 steps. It has taken a lot of time and effort to get it to where it is today and finally I have started getting serious about the pavers. Since I don't have a lot of time I can plan to dedicate to it, renting a wet saw is somewhat out of the question. So instead, I've been honing my skills with a masonry hammer and chisels. Each time I get deep into the work, I find a new technique or trick that makes working with the chosen materials easier. I thought I'd share some of those here today.

Landscape blocks are usually rated by PSI. Some have a relatively low PSI, akin to cinder blocks (the kind they use for basements and foundations.) Others have a higher PSI and hold up to the stress of freeze and thaw better. I have found that the harder the material (greater PSI) the more sincere you need to be, both in adopting the material (more PSI = more physical work to cut by hand) and when applying cutting force.

Some of the pavers I have are, if memory servers, in the 10,000 PSI range and take a lot of force. In fact, babying them seems to often cause them to break in the wrong spot as they are a little on the brittle side. The blocks I use, however, are closer to 4000 PSI and too much force causes them to break unpredictably. They like to be broken a little at a time.

In both cases, using a fulcrum for them to break over usually provides a straighter cut. I use a 3 " chisel for most cuts and drive it with a 3 lb. hammer. I usually clean up the cuts with a masonry hammer, using the chisel end for breaking down bumps and the flat end for smoothing rough areas. Also, using the 3 lb. hammer in combination with the mason hammer makes for a very finely controlled 1 " chisel. Just hold it in place by the handle and hit the flat end with the 3 lb. This is great for shaving rough cuts down just a hair with several quick taps. Often when I have two bricks to fit together tightly one needs just a shave to change the angle of the face just a few degrees and this gets the job done.

Also, when working with small stones, I usually work on top of a larger block and often step on the block I am cutting to secure it without mashing my fingers (good sturdy boots are indispensable in any regard). Today, for example, I had a small piece to fit in that was 1" x 2" x 2" and I had cut it down from a piece of scrap. Getting the edges straight on the last few cuts required liberal use of my boot and the mason hammer as a chisel technique.

The other thing that is great about high PSI pavers is that you can use them as a grind stone of sorts. I had a slender piece to stick between two other pavers and needed to smooth the cut side without destroying it. Hammering was out of the question. So, I placed it rough side down on another paver and used a rubbing motion till it was as smooth as the other paver. It fit in the tight gap perfectly.

I hope to have more time this summer, maybe even enough to finish the project, and more photos and tips to share. I hope you are enjoying your projects as much as I am mine!

Friday, May 4, 2007

Estimating Labor

Friend: "I'm in over my head. I started to redo x and found out it also needed y, z, and a bucket of p & q when I got into it!"

Answer: The Bible rocks. Luke 14:28 has this useful advice for avid DIYers:

"For which of you, intending to build a tower, does not sit down first and count the cost, whether he has enough to finish it"

I heard this same quandary from at least two or three people this week as spring has motivated the hibernating "real man" in many of us to get to tackling that never ending list of things needing doing around the farm, castle, etc.

I think these experiences help validate a DIY estimating formula I have been working on for the past few years as projects around our house have often gone the same way. It's taken 4 years to do the basement and this formula has allowed me to more effectively schedule work in the past months.

(1 layer material * Square feet affected * [material factor] hr) = Total Hours

Sheet material factor: .3 (cutting, installing, measuring twice first...)
Mixed component material factor: .6 (grout, mortar, specialty floor coverings)
Unmixed component material: .25 (paint, plaster)

In practice, I've come to consider a layer of material as separate jobs. Tiles = 1 layer and grout = another, so tiling the 6 ft by 4 ft (- 2 sq ft for vanity/sink base) should work out:

Lay tile:
(4*6-(1*2)) * .3 = 6.6 hrs

(4*6-(1*2)) * .6 = 13.2 hrs

Total Estimated hours (not including beverage breaks, football breaks, naps, etc.)
19.8 hrs - or most of a weekend.

If I have to level the floor or cut and lay down sub floor ahead of laying tile, then I can figure on adding another sheet material time calculation:

Lay sub floor:
(4*6-(1*2)) * .3 = 6.6 hrs

I expect you could adjust for metric as well as factor in help. I typically have no help, but when my wife is available to lend an odd hand here or there it does speed things up considerably.

But obviously, this is far too general to be useful in all cases. The way I came up with it was to look back on all the DIY I have done in the past and honestly estimate the time it took. Really, football, basketball, beer... it really has to be factored in if you aren't getting paid by the hour to do this stuff. If you are your own boss, make sure you are honest with the boss. :-)