Mortar Mixed Wrong.....

[Truck Addict]

My garage in underway. We were laying 8" blocks today to get above grade. At the end of the day I noticed how much Lehigh Masonry Cement I had left over vs. the number of blocks laid. I was planning to use a 3:1 ratio of sand to cement. I was not the one doing the mixing today and it ended up more like a 5:1 ratio! I know that 5:1 works "okay" for above grade stuff but this is 2-3 courses below grade. The block wall will be parged and waterproofed (parging tar) on the outside. Also my total block height is no more than 5 rows. The slab will not rest on the walls, so the block wall will only be supporting the framing for the walls and roof. Should I be worried about this?
I know what happened........5 shovels of cement, 15 shovels of sand, but a shovel full of sand usually is about twice as much material than a shovel of cement.
If this is a issue I was just planning to fill my cells that contain my anchor bolts solid with concrete from footing to bottom plate....about every 4ft.
Thanks for the advice and info!
Truck Addict
UPDATE: So I was looking at my receipts today. Come to find out, the supply yard actually sent me out 3 extra bags of cement. I had asked for 10 and they sent 13. So all this time I thought my mix was light on cement based on the number of bags left over (since I THOUGHT I started with 10) So my mix was actually okay all along. This is the only problem with having so much help on a project...other people mixing, etc. so I never noticed the extra bags! I feel better!

 

[brownbagg]

its nine shovel of sand to one bag of mortar mix

 

[stout1]

its nine shovel of sand to one bag of mortar mix

How big is the shovel?

 

[Truck Addict]

I was going for a 3 to 1 mix. One whole bag was not mixed at a time. None of us are pros and it was also a small mixer. Instead the masonry cement and the sand were both shoveled. 5 to 15 is the same as 1 to 3 ratio. My question is about the fact that the ratio was really closer to 1 to 5 because of the improper shoveling of the cement.
Thanks for any helpful advice.

 

[discbrks]

I had to do the same thing for my shop to get it above grade, however the top coarse of block had a 4" notch in them. When I poured the floor, I filled the entire wall as well. Rebar bent at 90* into the cells and tied to the wire in the floor. If you're iffy about the mortar joints, then I would fill all the cells.

 

[Truck Addict]

Thank you Discbrks. I'll fill the cells. Probably not all of them but most of them. I talked with a friend that does a lot of block work and he laughed at me. Told me I worry to much and that the mix would be fine especially for such a short wall and low load.
I wish I could just let my slab pour into my block but my slab is below the top course. My garage is built into a sloping yard so part of my slab is below grade in the rear.
Thanks again.

 

[Zeke]

its nine shovel of sand to one bag of mortar mix

Not if he bought 94 lb. sacks. For a big project I wouldn't fool with 60 lb. bags.

I'd fill the wall, especially in the back where it's below grade. I would have done that even if the mix was rich. There's not a whole lot of strength at mortar joints, rich mix or not. The strength comes from vertical rebar and filled cells. Locks everything together.

If the slab is inside the walls, I'd also dowel in just below the proposed finish level. It doesn't take much, 3/8ths will do.

 

[Mike951]

I recently had a similar issue:

http://garagejournal.com/forum/showthread.php?t=121515

 

[joes169]

What kind of cement where you using? Type M? S? N?

Somewhere around 4 to 1 is correct.

Depending on what size/type of shovel you're using, as well as the moisture content of the sand, you need between 15-18 shovels of sand per 70# bag of Type M or S.

IMPO, a stem wall garage should ALWAYS have a floor ledge built into the top course, or whatever course is at the bottom of floor height. If you are laying a total of 5 courses, here's the optimal way to do so IMO.

First 3 courses are 8" regs.

Fourth course is and 8" solid top, with 8" regs at all pilasters.

Fifth course is 6" solid tops, with 6" regs at pilasters.

This allows fro a 2" wide interior ledge for the floor to sit on. If you're concerned about the integrity of the wall, you can also slide a 3/8" rebar in the small gap left in the floor ledge at the pilasters. This rod should extend 16"+ above the ledge, and later get's bent at 90 degrees into the slab pour.

One more thing. There's no benefit in tarring a garage wall, especially only one side, unless there is living space below.

 

[Truck Addict]

Thanks guys. Mike I read your posting about your walls. My joints are very hard and can not be scratched out so my mix wasn't as bad as your situation.
Joe, my area requires the parging on the wall, so I might as well tar it too. I'm also putting drain pipe around the footing since it is built into the sloped yard. My slab is about 2 courses below grade on the one wall, so my tallest wall is 5 courses (slab will be poured to the top of the second course)so my tallest wall above slab is 3 courses. Luckily I still have two courses to go on that wall, so the mix will be right for those! I'm just going to run vert rebar at each of my anchor bolt locations and fill those cells solid with either mortar or actual grout. Personally I'm leaning toward mortar unless someone can talk me into grout. I just don't see much difference in the two....at least as far as ingredients are concerned. Seems like every job I have ever been on has had anchor bolts concreted in, grouted in or mortard in...all 3 variants on one building. I guess just using up material! LOL!
As for my slab, it will not be tied to the wall, nor sit on a ledge. Compacted gravel base and then poured. I toyed with the ledge but didn't do it. I have thought about buying some 4" block and laying them up on the inside ledge of my footing up to the bottom of the slab height.....not a contiuous 4" ledge but rather spaced about 4' apart so there would just be lugs around the edge to rest the slab on. Not sure if this would be a good or bad idea since these points could lead to cracking issues if the slab wanted to settle and since it isn't continuous it could crack at these "lugs" The biggest reason I don't have a ledge is really an oversight on my plans. They got submitted with all 8" blocks on the detail and once approved any change like the ledge would have set me back 3-4 weeks for re-approval!
I've been involved with many "floating" slab projects so I'm not concerned......I think!

 

[ConCretin]

A bit off topic but several have mentioned tying slab into perimeter walls with rebar. In my opinion this is not a good idea as it would constrain the slab as it shrinks during curing. Slabs should be allowed to 'slide' inward to reduce likelihood of cracking.

 

[joes169]

Tarring & draintiling where the exterior is higher than the interior is a good idea, but below grade it doesn't help, and I'd be really suprised if any code required it on a garage.

"I just don't see much difference in the two....at least as far as ingredients are concerned."

There's actually a big difference, the mortar has large amounts of lime in it, which will corrode the rebar and anchor bolts. Small stone concrete works great for what you need. If you want to stretch it a little farther, you can throw a little extra mason sand in each batch. And don't forget you need either hot-dipped galvanized or stainless anchor bolts if using a treated sill plate.

As for the floor, I'd set the 4" around like you're thinking. The floor will already sit on the wall at every door opening, correct?? If the floor settles, I can guarantee it isn't going to settle perfectly across the entire floor. It's going to have more cracks & issues than if it was sitting on a ledge around the perimeter. Make sure to compact the interior stone/gravel in lifts, and you have nothing to worry about.

 

[kbs2244]

Just because I a belt and suspenders guy I would like to see the cores filled.

Can you use the notched blocks to go from 8 to 4 inch block at the slab level?
That would let you will all the cores easily and still bring your block up to framing height.

Or pour you slab to the outside of what you have now and the continue your block by laying it on the slab.

 

[brownbagg]

yall are beating a dead horse here, it nine shovel of sand to one bag of mortar mix. mortar mix only comes in one size bag. a shovel is a square point sand with sand on it. it will be the same no matter how you do it. Trust me. as a structural masonry inspector I see this everyday for 27 years.

 

[joes169]

yall are beating a dead horse here, it nine shovel of sand to one bag of mortar mix. mortar mix only comes in one size bag. a shovel is a square point sand with sand on it. it will be the same no matter how you do it. Trust me. as a structural masonry inspector I see this everyday for 27 years.

Either you have a big scoop shovel or you own stock in lime & portland. I've been in this trade for a "few" years as well, and I'd never lay mortar that was that full of cement, unless the shovel terminology is just that far different..............

 

[brownbagg]

i said mortar mix, I never said bagged cement

 

[rburke65]

A big bag here, a 60# bag, a 70# bag over here, a mortar mix, a bag of cement, a shovel With a 'square point sand with sand on it'. What ever that is?????? 4 to 1 verses a 1 to 3 or maybe a 5 to 15...... A big shovel.......what's a big anything? What the hell are you people talking about. I'm glad you guys are not making up my IV bag. My God............

 

[Truck Addict]

Thanks for the feedback.
Rburke85: I agree with you. Size of the bag or shovel doesn't matter. I was talking about actual ratios...
Brownbagg: I was using cement and sand to make my mortar.....not mortar mix. I had masonry cement and sand.
Joes169: Draintile around the perimeter in my case is added insurance. We have a high clay content so I wanted to make sure that any surface water had a fighting chance to drain away. Since my slab is below grade on the one side I want to make sure I don't have moisture issues with my wall.
Thank you for clearing up the mortar vs grout issue. I didn't realize the lime content. That makes me remember something at one of the raceways...I think it was the Lowes Motor Speedway. They had some concrete fail due to rebar rusting due to high lime content.
The block wall is done now, and the inspection is scheduled for Monday. I talked to the inspector as I know him through other work and he assured me I won't have any issue with my wall. He used to do this type of work until he became an inspector (health issues won't allow him to do the hard labor anymore) I told him the whole story since I didn't want to hide a potential issue just to pass inspection.
Anyway, thanks everyone for the help and suggestions. Next time I'll get our shovels calibrated before laying more block......

 

[pstnbly]

In clay soils with a high water table I would provide drainage and damproof the foundation with asphalt. I made a nice living over the years digging up foundations and replacing rotten block walls that wern't damproofed. You can literally peel 30yr old block away with your fingernails that wern't protected around here.

 

[Truck Addict]

PSTNBLY, I fully agree with you. I'd rather pay a little now in "extras" rather than dig it up later.
By the way, read my update in my first post. Basically, I didn't have a mix ratio error after all. I was sent too many bags of cement and didn't know it. So when I counted what was left I thought I hadn't used enough! I ordered 10 bags and somehow they order went through as 13. Anyway, I'm sleeping better now nowing that my mix wasn't compromised after all!
Thanks guys,