Best Tool for the Job?

[dkerfoot]

I live in a 90+ year old house. My basement is made of cinder blocks, with mortar that has degraded over time in two of the walls.

Last year, using my favorite powertool (a 21 year old son who was still living at home) I removed the crumbling mortar from about 20 feet worth of wall and replaced it with hydraulic cement. I basically had him scrape out whatever was the least bit crumbly from a 4'-6' section at a time and then backfill it with the hydraulic cement. Combined with some regrading of the yard and some waterproofing paint, it was a complete success in stopping the water from coming in.

Now my son has moved out and I need to do the next section of wall myself. So, what powertool would work best for removing the old mortar? Fast and easy is always good, but I do use the room in will be working in as an office, so keeping dust to a manageable level is also important. Especially because I think it is best to work in small sections again, instead of doing the entire wall all in one day. Removing one side of the mortar from 20' of wall would make me nervous from a structural integrity point of view.

An angle-grinder with a diamond blade would certainly do the job, but create a nightmare of dust. Would a multi-purpose tool be the answer? I have never actually used one, so I am not really sure if it would be the right tool. How much dust do they kick up? What blade should I use? How many blades would I go through? Would the HF model be up to the task?

Is there a better tool I haven't thought of?

.

[Uncle Cracker]

There are grout blades available for the multi-tools, but I don't know how they would perform on hardened mortar. And I suspect that the HF tool might be a bit light in the shorts for such a task. I think I'd opt for a small pneumatic hammer, like this one from HF. It's 10 bucks (before any coupons). Wear eye protection!

[knobcreekman]

I don't have any advice....

... I was hoping to get some though i have a cinder block basement that seeps as well and have been wondering what to do about it. Did you only put the hydraulic cement on the inside wall? I've heard of some people drilling holes and actually filling the inside of the blocks with the hydraulic cement. Also, was Dry Lock what you used for the paint? We just have seepage that comes in when it rains for days on end (which it does often where i live) and i'm just trying to get some feedback if this is a good option from someone who's actually done it...

BTW... I'M NOT TRYING TO HIJACK YOUR THREAD... if it comes across that way just let me know and i'll delete this

thanks

[dkerfoot]

. I think I'd opt for a small pneumatic hammer, like this one from HF.

Have you used this? My concern would be that it would jump around too much. I need to remove the mortar but not damage the blocks.

Regarding "hardened" mortar, I should not that my son used a a plain old 5-in-1 scraper/window glazing tool, so hardened isn't a word I would use here...

[dkerfoot]

... I was hoping to get some though i have a cinder block basement that seeps as well and have been wondering what to do about it. Did you only put the hydraulic cement on the inside wall? I've heard of some people drilling holes and actually filling the inside of the blocks with the hydraulic cement. Also, was Dry Lock what you used for the paint? We just have seepage that comes in when it rains for days on end (which it does often where i live) and i'm just trying to get some feedback if this is a good option from someone who's actually done it...

BTW... I'M NOT TRYING TO HIJACK YOUR THREAD... if it comes across that way just let me know and i'll delete this

thanks

No problem jumping in with the question. I did just put the hydraulic cement in the inside, except for the area where my electrical panel is located. I did the same treatment in that area outside and extended it a couple blocks beyond the panel.

In my case, the only significant water seepage I was getting was through the mortar. there was little if any through the blocks themselves.

No waterproofing will work if you have standing water against the house. If your yard slopes towards the house, that is job #1. If you can't or won't fix that, I'd say don't bother with the rest. Properly functioning gutters can make a world of difference too.

For WP paint, I chose Zinsser Watertite. if I remember correctly, it had better specs for water resistance and had lower odor. I painted both the wall and the floor because I was installing bamboo flooring and wanted to vapor-proof the floor.

Worked great for me, but as always your mileage may vary...

[cabinetman]

I've used the HF multifunction tool with the diamond edged attachment, and it will remove the mortar, and not make a lot of dust. It would likely be easy to control.

The air impact hammer used with the flat chisel will also work. I replaced 21 windows in cinder block/mortar with that tool. You won't wear out the chisel, and if you modulate the air with either the trigger or a regulator, it won't jump around. Place the chisel where you want it, press, and lightly squeeze the trigger. You'll pick up the feel quickly on how to move it around.
.

[phi1l]

This may not be practical in your basement, but if there is a floor drain near by, I would first use a high pressure cleaners with the nozzle set as highly focused as possible. It will definitely remove any loose mortar faster than anything else, but you will need to cover anything near by that you don't want to get wet, & if you don't have a nearby floor drain, forgetaboutit.

[cgallery]

As someone that used a multitool to remove all the parging from one basement wall (thank GOD only ONE was parged), I can say that I think that using one to remove the mortar would be a long, painful process.

Is the mortar sound? I know you have some success behind you w/ the hydraulic cement, but do you have to go to those extremes?

After removing the parging I found gaps/holes in my mortar beds but I was able to fill then. I had some small gaps I filled with a latex product. Some larger ones (primarily a corner) were filled w/ hydraulic cement.

[Uncle Cracker]

Have you used this? My concern would be that it would jump around too much. I need to remove the mortar but not damage the blocks.

No problem... Just keep the pressure turned down to where the tool just starts to hammer (around 40-50 psi should do it), and it won't get out of control. You'll be able to keep it where you want it. Depending on your compressor, you may have to pause from time to time to let it catch up, as the tool might use 4 or 5 cfm.

[herb fellows]

I had a similar situation with a bluestone wall in my basement. Mine was also one wall only, fortunately.
If the mortar is more loose than not as mine was, and you don't need to go too deep (mabe 6" max?)and the mortar between is maybe 1" thick, you might do what I did. I used a medium duty hammer drill (not a monster, just a regular sized drill) with a 'drill bit' that had side cutting capability. I would say I cut out about a foot in 3-4 mins on average with this method. Because yours is cinder block, at least the amount you need to cut out will be consistent., mine was all over the place because it was stone.
If it's too hard for the side action to work, you may just need to get a mortar bit and drill in every few inches and sort of hog it out.
You are right about the structural integrity. definitely keep it to a few feet at a time. I did maybe 3 feet, then I would move 10-15 ft down the wall while the hydraulic cement was drying, then after a few days move back to the section next to the first one etc etc.
If you can attach a vacuum hose to a roller stand or similar , you can move it along to be near to the area you're drilling and help keep the dust down.

[dkerfoot]

If the mortar is more loose than not as mine was, and you don't need to go too deep (mabe 6" max?)and the mortar between is maybe 1" thick, you might do what I did. I used a medium duty hammer drill (not a monster, just a regular sized drill) with a 'drill bit' that had side cutting capability.

Interesting approach. For the record, I would remove mortar no deeper than 2" max and it is more like 1/2" thick.

[DustyandLefty]

another vote for the multi-tool

I've seen the dremel grout removal blade work fast while making the least amount of dust. If the mortar is soft and 1/2 inch deep, then the multi-tool would be my first choice.
(somewhat) Dusty and (always) Lefty