The mortar on a rock face concrete block foundation of my house is in bad shape. I had intended on repointing it all next year, but one wall requires attention now as the landscaping is starting to takeover.
What tool would you all recommend for removal of the old mortar? Can I use an angle grinder or would an impact hammer with a chisel bit be appropriate?
Anyone know if there ar specialized tools for this task that I might be able to rent?
Replies
A chisel bit in an impact hammer would be the more awkward to use as there be more likelihood of chipping the edge of the face of the block. I'd use a grinder.
Why has the pointing deteriorated? -- efflorescence? You may need to cure whatever it was so that the new pointing doesn't go the same way.
IanDG
the problem is two fold.
First, the section of wall and foundation in need of repointing never matched the profile used on the original house. The mortar lines on the 1916 house were all rounded over or convex. I want to duplicate this profile on the 1922 addition as well as the brand new addition I will be working on.
Second, thge mortar on the '22 addition looks like it was repointed in spots at some point in time. The job was poorly done and spotty.
My intention is to clean up both problems.
I'll try a grab a picture and post it a bit later.
The mortar lines on the 1916 house were all rounded over or convex.
I know the joint you mean -- it's done with a jointing tool and it replicates "Cut and struck" without all the work involved.
Forgive me if you already know, but the mix should be about 6:1 sand:cement [lime isn't necessary with concrete block, or advisable for foundation masonry] and should be wet enough that a handful stays as a lump when squeezed together but not wet enough that it sticks to your skin.
Damp down the existing joint with a fine spray and pack the mix into the joint with a pointing trowel then tool the joint with the jointer -- doing perpendicular joints first. Brush off any crumbs with a fine-bristled brush.
It's a slow process and best done on an overcast day.
IanDG
"...doing perpendicular joints first."
?? Uhh, perpendicular to what?? I'm guessing you meant to say verticle joints first????
Rich Beckman
Another day, another tool.
UK terminology, Rich -- perp joints usually.
IanDG
Over here we have "head" joints and "bed" joints.
4" diamond tuck pointing blade in the angle grinder(pick the width that best matches what you have), blow out all the dust, dampen down the wall, grout bag a slightly wetter mix than IanDG's into the joints, let it stiffen, and get out the jointer and strike the joints and brush.
Thanks to you and Ian both. I am just a homeowner and have never tuckpointed before, although I have layed brick and block.
Think I might buy one of those cheap "made in China" angle grinders and spare my Dewalt. I am guessing this will create a lot of dust and that can't be good onthe motor. For $20, I can consider the cheapo grinder disposable.
$20 for a grinder!!!
i picked one up for a friend for £7 (~$10)
but in my experience the dust doesn't do grinders too much harm, you just got to clean them out.
i've had a 9" bosch for well over 5years and its still going strong its cut 1000's of bricks paviors etc....
before you take a grinder to the wall had a quick poke about with a screwdriver or cold chisel you may find that the motar is as soft as cheese and will just scrape out but hand.
You might want to try using your angle griner tool to fabricate a tool for removing the old mortar from the joints.
Talk to a fellow at the closest Tool & Dye manufaturing plant & get some insight from him. Maybe they can even design & fabricate a tool to make your life easier.
Chipper 6/6/04
I have seen an angle grinder with a tuck pointing bit or wheel used. I have seen a circular saw used with a masonry blade set at the proper depth, this method offers alot of control, and a fixed depth. Wear a respirator!
Once saw one of these cool specialized pneumatic tools in action cleaning out mortar joints with soft brick and fieldstone. One more thing on my dream tool list... Not cheap, but easy to control, and easy on the surrounding masonry. Your concrete blocks may not be fragile enough to require this level of care. Plus, you probably have straight joints (unlike stonework). A grinder may be faster.
http://trowandholden.com/restore.html
View Image
Nice illustration. I assume you borrowed that from somewhere...or are you an illustrator?
I have seen several old stone houses here in south Texas where the limestone bears marks from something similar to the 4-tooth ripper.
Whenever you are asked if you can do a job, tell'em "Certainly, I can!" Then get busy and find out how to do it. T. Roosevelt
Ed,
That image was from that manufacturer's website. It's really a stone carver's tool. Some historic masonry contractors use this pneumatic tool for repointing over grinders because they are less likely to damage soft brick. It's like using a hammer and a plugging chisel, but a whole lot less effort. Also, a 4-inch grinder is too big to dig out the vertical joints in brick without hitting the courses above and below.
A stone barn near me was restored using these tools, and I got a chance to try one out. The fieldstone joints were too irregular to use a grinder. Very easy to control, and so much faster than hand tools.