Brick salvaging: practical tips?

In my opinion using salvaged materials is the ultimate in green building. However, it's not always easy!

On our acreage there's a collapsing former rental house that I was guessing was 70-90 years old. There's a back porch that clearly was made of salvaged materials itself -- it's got three kinds of brick, two kinds of cinder block, and a bizarre three-chamber fragile cinder-block-like thing made of brick material, all jumbled together and held by some extremely hard and strong mortar that seems to be full of quartz or granite crystals.

I attacked it today with a tire iron and a claw hammer -- surely not the right tools but they were ready to hand. I want the bricks and cinder blocks for edging garden beds; my ancient mother in law employs a guy with a huge riding mower to keep a big chunk of yard mowed, and anything I carve out for plantings needs to be edged in a solid and visible way that will emphatically deter a power mower going thirty miles an hour.

My problem is that the hollow-brick-block materials are extremely fragile, the bricks themselves are prone to crack, and the mortar is both extremely hard and extremely well bonded to the brick material. I'm getting about a 50% breakage as I pry the blocks apart and attempt to chip off the biggest mortar chunks.

The hollow brick blocks are inherently fragile, so that's no surprise. But I'm not doing that well with the genuine bricks, either. I know that lots of people salvage bricks. There must be tools, techniques, tips, hints, procedures. Anybody got any suggestions on how I can up my recovery of clean unbroken bricks and blocks?

Here's a picture of the project when I was just getting started. It turns out I can date the house very precisely; I found a "6/6/46" inscribed with a nail in the mortar of the porch. Of course that could just be when the porch was built, but in the picture you can see that the house sits on pylons made of the same stacked 3-chambered hollow brick blocks that the porch is made out of. So, either the house and porch are of the same date or there was a pile of foundation bricks sitting around when the porch was added later.

Brick salvage. Your input on best practices?

P.S. This crumbling house also has a large brick chimney that will probably long outlast the structure. I don't have the scaffolding to take it down brick-by-brick from the top and I don't think it could be toppled into my yard for easy access without a bulldozer-and-winch or a colossal excavator or some very hairy sapper work with a shovel and a hard hat. But in my heart I am lusting after the bricks, and have found myself idly wishing for an earthquake to topple the chimney for me...

Dan, I've processed hundreds of thousands of bricks. I wrote out a guide to doing this on someone's thread a couple years ago. It's quit exhaustive, no brick unturned. Hold tight and I'll look. This may take a while.

Those hollow blocks in the photos are used for insulating a masonry building. There's a good chance that they would not withstand freeze thaw cycles. The mortar you're dealing with has Portland cement in it. Lime mortars are much easier to deal with.

Thanks, Dale. I did search, spent about a half an hour at it, but I didn't find your guide. Honestly I figured you must have addressed this at some point!

Pool acid. To dissolve the mortar.

You don't have to dissolve it all away, just enough to weaken it so that a tap with a chisel will get the brick to pop out. Now working with full strength pool acid can be dangerous, so you may want to dilute it up by pouring it into a gallon jug that is 7/8 or so full of water (always add acid to water, never the other way around). At that strength you have a lot less chance of getting burned. Still, this is a job that you want rubber gloves and eye protection for. Since you are outdoors, just check the wind and make sure you are upwind when you pour it on the stoop. Give it a good half hour to work and then when you come back to work on it, rinse it down good. Test which bricks have been loosened up and pry them away. Then give it another acid treatment. It may take a few cycles, but dissolving the mortar away is going to salvage a lot more bricks than trying to hit the chisel in just the right way.

Pool acid? Fascinating!

However I've worked with strong acids and didn't much enjoy it. I suspect that at the end of the day I'm going to do my best with brute force and any finesse I can bring to bear, accepting inevitable losses along the way as preferable to the risks of messing with strong chemicals. I already had brick chips rattling off my eye protection today, last thing I need is them bouncing into my hair and dissolving holes in my scalp.

John

Dan, I'm still looking for the brick stuff. Check this out. Lots of demolition stuff. --- https://permies.com/t/9838/green-building/DeConstruction-Bulding-Salvaged-Materials

The pictures show the brick and mortar to be in a bad state. I'd guess freeze/thaw cycles have already cracked the mortar. Hitting the brick with steel will shatter and chip the brick. Rather than brute force, go with finesse: use a rubber mallet. You'll get some of those bricks real easy. They will still have mortar in spots-chip it off with a small pointed hammer.

Pool acid will react with the lime, causing the mortar to disintegrate, but it is a slow process. You might try getting between the brick with a wood chisel. The chisel will be ruined but can be reground. With the mortar in such a bad state, the chisel will act as a wedge, pushing the break apart where the mortar is already cracked. You can further weaken the mortar joints with a masonry bit and a drill. Filling the drill holes with dowels, then soaking the dowels can give you a more gentle force as the dowels expand.

Dale Hodgins wrote:John

What? I didn't put enough CAUTION, DANGEROUS CHEMICALS! disclaimers in? That's how I clean up old bricks. Of course HCl and I have an understanding, I treat it with respect, and it doesn't burn me.

John Elliott wrote:

Dale Hodgins wrote:John

What? I didn't put enough CAUTION, DANGEROUS CHEMICALS! disclaimers in? That's how I clean up old bricks. Of course HCl and I have an understanding, I treat it with respect, and it doesn't burn me.

I thought it would be fun to give a pictographic response. I drive with my knee while eating and yapping on the speaker phone. This is far from best practice, so I don't advise less talented multi-taskers to take up the practice.

Dale, I have been reading that thread all evening. It's very long. That's how I knew you would have useful input on this question.

John, you had plenty of disclaimers. It's one of those things where I know that your method would work, I just don't think it's for me. I would screw it up and be screaming under the garden hose.

Ken, a big part of my problem is that the mortar is doing a lot better than the brick. It's all in a bad state, but the mortar is surviving better. Fortunately, even broken bricks work pretty well for my edging purposes as long as I keep the parts together.

An angle grinder with a diamond blade can cut into the mortar, separate the brick.
Since the brick will still be exposed to the elements, using chunks of several bricks stuck together may be the way to go. They will be heavy. Left exposed to the elements, they would continue to crack on their own but at least they would be in a non-load bearing spot.

My recovery rate went way up today. What I've learned so far: Strike the mortar with my hammer; never strike the brick. The brick is fragile, the mortar is robust. But the mortar's adhesion is frequently poor. It can, and sometimes will, pop completely off when smote properly.

Strike on an angle, never a direct blow. A light hatchet or roofing hatchet can sometimes work. When cleaning the final bit off bricks, rub two bricks together. The gap should be vertical so that mortar dust can fall. If you ever get bricks that can be cleaned for future use, cover them with rotting leaves. The tannic acid gets between brick and mortar. If you get lots of freeze/thaw cycles, lay the bricks in a rough pile and spray with water before the frost. Much of the mortar will blow off and worthless very porous bricks will spall so you can identify them.

Sweet! I am doing this under a huge hackbery tree so any bricks I don't use for edging this summer will be easy to bury in leaves come fall. That will not be many, just a small pile of whole bricks that are too good to waste in garden edges.

Right now I'm getting a lot of the fragile hollow bricks that are whole and clean but for one mortared surface. That's good enough for my purposes; I can just bury that surface.

I think it will go much easier once you get past those outer bricks with the smear coating on them. There is a such thing as a mason chisel. I've used a steel chisel. If you can score that smear coating in line with the joints they'll be more apt to pop apart on those lines. It doesn't have to be real deep but does have to be full length. You're basically encouraging it to break where you want it to. Same way masons cut bricks and stones before saws were around. On the lower ones if you can get a pry bar in there, they should pop apart for you. A wide bar/blade is best. That tire iron puts pressure on too small of an area. You need an actual wrecking bar. Mine is 1 1/2" wide by 3/16" thick at the ends.

That looks like a very useful tool! So far I've been lucky; this whole porch had lost its structural integrity, so except for three blocks from the bottom step that were deeply bedded in mortar, I haven't had any trouble getting the blocks apart or detached from the structure. At most a light pry with my iron or a single rap with my hammer has done that job. All the damage I've been doing to my blocks and bricks has been from trying to break them free of the encrusting mortar. Construction method on this porch was sort of "stack the blocks up any old way and then pour mortar on top, trowel until it looks square" so the mortar is sometimes inches thick.

But yes, it's become very clear to me that my tire iron and $5 claw hammer are not the best tools for the job!

The basic shape of those DeWalt bars is right, but the whole design is poorly executed. The metal is too thick at both working ends so that it's hard to get the tool into a crack. I've had them and used a grinder to re-manufacture the tips. Weight distribution is off, with too much in the shaft and not enough in the rounded end. Notice the angle bend about 8 inches from the foot. Bars work better when there is a sweeping curve rather than an abrupt angle. When quality salvaged wood is popped apart, this bar will dent it. Lee Valley sells similar looking bars that are lighter but stronger and of much better design. The curved end can be used like a sledge to knock wooden framing apart. There are other vastly superior bars from Sweden which look like this but incorporate all of the improvements stated.

Yeah, mine's a lot thinner too. That was just a pic of the general design. First pic found with a web search for wrecking bar.