Cinder Block Repair

[rodwerkz]

My shop is a 60+ year old 35wx35lx18h block building. It was originally a garage for milktrucks and now houses my dangerously old metalworking machines and hotrods.

My shop borders my neibors on three sides so i can only see the front wall from the outside. I noticed some light showing through the seems in the block on one of my shop walls. With my neibors permission I went on his property to repair the crack this weekend.. unfortunately the shop walls are alot worse than i expected. the 60 year old walls are deteriorated and there are some sections where the concrete has totally run out of the seems between the block. Unfortunately the neibor facing walls were never painted or maintained.
I have a few questions:
1. What is the best type of concrete to fill in the cracks? I've typically used quick set since it sets up quickly on verticle surfaces.
2. I'm having trouble working the concrete into the voids. I almost wish i could pipe it in somehow? What is the best method, tools for doing this? Is there a special tool or method for getting the concrete into the seems?
3. On the smaller hairline cracks should i consider using that crack repair stuff that comes in the caulking tubes?
4. What is the best paint to use to seel the concrete? Do i need any sort of sealer before i apply the paint?

Any advice would be appreciated.

 

[W-Cummins]

You want to use mortar _NOT_ concrete. You can use a grout bag if you want to apply it. Get some tools for re-pointing brick to help get the mortar deep into the joints and to smooth out the joints.

William

 

[rodwerkz]

I apologize but i'm a little ignorant with this type of work. this definitely helps.

 

[Rrumbler]

Check with the hopefully friendly folk at a local concrete block yard, not Lowes or HomeDepot; they are, or should be, able to give some pointers, and have the tools you'll need. Basically, a grout bag is a large coated canvas, or heavy poly bag with a metal spout attached; you mix your mortar in small batches (if you're working alone) to about the consistency of cake frosting, fill the bag, and start squeezing the mortar into the joints. Pointing tools are small trowels, sometimes flat ended, and joint dressing "rakers" are a bar type tool that is used to smooth the mortar in the joint and give it the surface needed to resist the elements. Cleaning the joints to be repaired is an important part of the process; all of the old loose mortar must be removed, and the joint surfaces free of any loose debris. Some masons will "re-wet" the joint by spraying it with a spray bottle, or dampening it with a wet sponge, to help the mortar cure more evenly.

 

[JeremySmith]

Are the blocks sound, and the mortar is what needs attention? Call up a couple masons, and have them come out and take a look at repairing the wall. It probably just needs to be tuckpointed - which is where they grind out the old grout in the joints and replace it with new. If the concrete block has started to crumble, the mason can repair that, too. That part of the work should be left to a professional, you're talking about the structural integerity of your garage! After the repairs have been done, take a few photographs of the sides that you want to coat, and then go to a masonry supply house (ask the mason for a good one) and then show a salesmen the pictures and tell him you want to parge coat the walls. A parge coat is basically a thin grout that you spread over the walls to protect it. Then if you were really dead set on protecting the walls, spray a good coat of paint over it all. Do all that, and it'll be solid until long after we're gone.

 

[rodwerkz]

The blocks are ok.. just the surface is getting very weathered and the surface will dust really bad when you run your hand over it. It's really just hte mortar that needs immediate attention.

I'm going to try regrouting it myself. the grout bag should make things alot easier. thanks for this advice. I hadn't heard of one of these before but figured something similar must exist. I found one at home depot during lunch.

The good thing is that the garage is severly overbuilt. The whole perimeter of the garage is framed out with 12" I beams. So there's no risk of it falling down.. I don't think the walls have been structurally comprimised either, i just want to stop them from getting worse..

thanks all for your advice. This really helps. I've been doing some research in parallel myself.