I have found that clear sealers don't work, CMU's are so absorbent that the only thing that works is paint. I parge below grade to seal pores before applying asphalt waterproofing.

Is there a basement? If not leave it raw and insulate it from the floor.

See if any of these scenarios are useful. https://grace.com/construction/en-us/waterproofing

Thanks all. 

Maybe I should describe the situation more. For below grade, I am definitely waterproofing on the exterior side of the CMU with self-adhesive mod bit waterproofing membrane with dimple drainage board on top of that. That location that I'm undecided on is the face of the CMU above grade. Parging is normal practice but its the cheapest, fastest way but the most unreliable, not durable, and unsightly.

So that brought me to the 100% acrylic clear sealers, as the one I mentioned above. I was just wondering if anyone had any experience waterproofing the CMU above grade with this method, especially if you are in my region where there is often rapid freeze-thaw cycles in shoulder season and used an alternative to parging. 

Thanks in advance.

Olaf Design Ninja_, 

Yes there is a basement where top of slab is about 8'-0" below grade. 

I second what Olaf said regarding Grace products. 

You might also check out the info at http://www.buildingscience.com/

It might sound crazy and I don't know your circumstance, but once upon a time, somebody suggested to me, to use metal flashing.  To be honest though,  18" is a lot of exposed flashing at grade.

I'm in Canada too, never heard of Grace before so not sure how commonly they're spec'd.  Instead we tend to go with soprema (soprema.ca) for waterproofing, however that doesn't answer your questions about the surface finish.  There are some stone and concrete veneers (ie thin blocks) that are approved for being in contact with the ground in this application, although it's late Sunday/early Monday and I'm many beers deep, so I can't think of any specific products off the top of my head. I usually start here though: ixlmasonry.com

Bad idea. Flashing corrodes and gets beaten up by lawn mowers, weed wackers, snow shovels, etc. 

Pour the wall with waterproof concrete.

Too late for OP but this is the ticket, love this stuff, high density not requiring coating.

http://www.classicrockfaceblock.com/

Is this addition already built?  And, reiterating -- is there a basement?

If it's not built yet, you have a great opportunity to solve several items at once, including water management and insulation.  Post the wall section.  

Checked, OP said  "there will be new addition at the rear with new 12" CMU foundation", operative words "will be". Assume 12" = basement.

^ not quite.  Tense shifts a bit in second post.  And I tend to not assume, thanks.  

Thanks for the comments everyone. Didn't mean to start any debates... 

Yes there will be a new basement. Yes 12" concrete block for new portion's foundation. 2' is a lot of exposed foundation relative to 'normal' foundations, but older houses are set up this way so I want the new foundation to follow that datum. Anyway, I think I solved my problem. 

For anyone who wants to know for future, I am waterproofing below grade portion with conventional waterproofing membrane and dimple board on the exterior face. Above grade, I am leaving the face exposed but will have it sealed with a Silane-Siloxane based clear sealer, which allows water to bead off the surface of the block but maintains the vapour transmission out of the block (block will still be breathable.) It will also deter salt corrosion (harsh winters here). 

@Carrera, I actually have this rock-face veneer on the existing portion of my foundation. Too traditional for what I am trying to do at the rear extension. But thanks for showing it here.

Thanks for the discussions and debates everyone! :) 

p.s. @bowling_ball I usually spec www.soprema.ca as well. Good to know others back up the spec. BlueSkin also has similar products if staying with the same manufacturers for building materials are a goal. 

You could use an epoxy coating.  It does require the appropriate block filler though. For a smooth finish. 

Other ideas are like those stones above.  There are some that are thin.  Basically you incorporate a full lath system and coating and apply the stone faces (think tile set).  You can get proper lapping over the damproofing when done right.  There are also exterior tiles too. Just be sure to flash over the top properly to keep water from getting down behind and maintain proper clearances to grade to keep it from wicking up.   

A cementitous breathable parge coat though is the best looking 'value' option though... you can get 'fancy' with that finish coat.  Locally here there was a builder who trowelled micra flakes into his for a different effect on his 20's development.  I've seen others get 'creative' embedding pebbles and so forth into that final trowel or false tooling to achieve a cut stone look, etc. Start looking at a lot of 1900'ish buildings since the foundations were often brick yet they wanted that more expensive cut stone water table look.

We've had this debate on here a few times, and it's still a question I struggle with - how to have a durable, affordable and attractive surface between grade and where the "siding" starts. 

The best is expensive, and it's debatable what the "best" is. 

I'd vote for a dual thickness of block (say 8" structural and 4" face) with rigid insulation between them. Below grade waterproofing as you describe and the silane/siloxane sealer (get it mixed into the blocks if you can). 

Even better - same thing but poured foundation. 

But it's expensive to do dual wythe w/the rigid insulation. 

If you do want to do something "nicer" like a metal at grade, might be wise to do a 2 foot (or more) wide "maintenance strip" around the building - essentially a gravel (or even cobble-sized) french drain. This keeps plants, weed wackers, people, etc away from the building and the rain doesn't splash dirt onto the foundation wall (as much). 

I personally don't mind the look of CMU or cast concrete at grade. I prefer a ground face style CMU if exposed, although split face looks better to the general public. The cast "split face" style that Carrera showed is a classic look, not sure if it's still available - that looks 1920's vintage to me. 

oops. missed that carrerra gave the link. cool to see that it's available. 

@gruen, Ideally, I would love to just expose a poured foundation. But block foundation is always cheaper and this is where my question started. I am actually going to have insulation on the interior face between studs so I'm not sure if I'd need the dual thickness method. 

I'm staying away from any metal at grade. Snow and rain will totally dent, scratch, and rust  pretty fast. I also personally don't mind exposed block, as long as the block is new and in good shape. I'm going to be doing ground face block for this modern look I'm aiming for. 

.dwg, I like your solution - but if you can afford it, do a layer (1.5 or 2") of rigid insulation inside the foundation wall before you put the studs and batt. I think http://www.buildingscience.com/

has some good walls to look at, but when I went to the site their high r value foundations was blank. (??)

^^Carrera

to go along with that post- In lieu of standard CMU, what about using a ground-faced or decro-face block?  It can be provided in a color and likely with dryblock additive...

Any hard face CMU would work without the cost of parging/coating but nothing works on standard CMU or split-face other than paint, including Dry-Block…painted three projects at my own expense before I got that point though my head…not a big deal for the OP.

Thanks everyone. @Jerome S, yes I agree. I'm going with ground-face block but just the standard grey. I want to keep it non-speckled with minimum aggregate showing. 

OK I have a possible dumb question related to CMU. I haven't detailed a CMU foundation in a long time. After laying the foundation, what goes on top of the final block? How do you 'cap' the last row that is laid? Is there something that is supposed to tuck between the top of CMU and sill plate? I would like to prevent pests and radon. This is wood frame construction. 

@gruen, thanks for the link. I'll keep this bookmarked. I actually haven't heard of the site before, probably because I'm based in Canada. Time to work on my continuing education hours! 

http://www.buildingscience.com/documents/bareports/ba-1003-building-america-high-r-foundations-case-study-analysis

Has some great info on designing basement walls. It is more about vapor control and insulation. 

@ .dwg

The way I have typically detailed the top of the wall and I believe is typical:

Cap course could be solid or semi-solid unit, depending on what's available from the block manufacturer.  It would also not be unusual to grout the top course solid.

Once capped, termite shield (in my area) then a sill seal (a closed cell foam strip) followed by your sill plate.  For the termite shield I prefer metal, I think some use other material.  This overhangs or is provided with a drip edge to deter the tubes termites build.  The sill seal foam strip is made for this use and matches the width of your sill plate.  It will compress and take up any irregularity between your sill and the top of the wall.

You should be all over this building science thing .dwg. All the good building scientists are from Canada, including those authors of the paper gruen linked (see here and here). If they aren't from Canada, they probably went to school there. If they didn't go to school there, they probably worked for someone who is Canadian or went to school there. At any rate, the good ones almost always trace back to Canada somehow.

Keep in mind that your penetrating water repellent will wear off after a number of years. But the good news is, that it probably won't matter, because you're building a mass wall. Just make sure you deal with moisture and vapor drive and you should be fine. 

http://www.buildingscience.com/documents/digests/bsd-103-understanding-basements/

working on a similar detail at the moment....I see one of my framing CMU block foundation details show's a termite guard, not sure about Canadian Termites?

---------------------------------------

.dwg you remind me of funny story with your detail question.

Had to raise a house due to new FEMA (flood map) requirements - damn Sandy.  The house needed to install flood vents to allow water to pass through in case of a flood.   It used to be if you had a slab on grade (SOG) you could use that as a diaphragm when the water pushes up against the foundation.  Either way, I didn't want the flood vents to end-up right below the sill plate and I took a quick look at the topo survey and figured the following statement would work

"Install Flood Vents ### min. one (1) course below sill plate" or something similar.

The surveyor for the insurance company surveyed the property and noted some vents were over 16" above grade at certain locations.

A few conversations.  Said - well grade the site so they are not, the contractor must have moved the damn soil.  ;)

next time I write that note "Install Flood Vents ### min. one (1) course below sill plate & max. 16" above grade"

lesson learned.
 

 I am actually going to have insulation on the interior face between studs so I'm not sure if I'd need the dual thickness method. 

Gruen and Everyday Intern then posted the Building Science links you should look at -- I second that advice.  

The method you're describing in the quote is going to be much more prone to moisture problems -- this method never seems to work over the long term.  In Everyday Intern's link, look at Figures 10 and 12.   Well worth the extra effort.

Cap course could be solid or semi-solid unit, depending on what's available from the block manufacturer.

Just curious, not sure what this means?  Depending on several factors, you might have a bond beam at the top, or you might not.  Either way you'd have vert reinforcing and sill anchors, both in solid grout.  How would a solid block under the sill work?  Maybe I'm misreading.

The top course doesn’t need to be solid; all that’s needed are anchor bolts for the sill plate which need to be set in mortar filled block cores. The other cores can be void.

The top course doesn’t need to be solid

Yah.  I was wondering how this person was going to make it work as a solid block.

However, I'm getting a kick out of your assumptions, Carrera. 

What'd ya call it again?  A sill anchor?  I'll have to google that...

Meh... I'm still floored by cmu block foundations.  I've seen too many failures to make what cost savings you had nil. 

^ Agreed. 

If the OP is building in Canada, there may be the need to apply insulation to the exterior of the block wall foundation depending on the size of the reno and provincial code.

I however agree with MightyAA and Miles above. I did a small, 30' long, CMU foundation repair job a few years back and the cost to fix/find leaks is too high.

Ha.  Well, I've never spec'd a block foundation wall.  All poured.  And, proper insulation continuous insulation is yet another battle on top of that one.

But alas, that is not the question of the OP, who is apparently off to the races laying up 12" CMU and spraying sealer.

In my area, a solid cap course is typical: sometimes it's a 4" unit, sometimes grouted solid.

in residential construction, there is not always vertical reinforcing.  The IBC spells out he max height and max backfill on a CMU wall by width of unit and soil type.  In fact, I have never experienced a bond be utilized in single family, wood frame building.

as to where to put the anchor bolts or sill straps; use you imagination- their are joints between units.  You could even drill and epoxy if you wanted to...

IRC/IBC says anchor bolts are not more than 12" from ends of sill.  Lap the sills right and you can locate the bolts in the joints between units, requiring no special detailing.

JeromeS, the IBC is not relied upon everywhere and local codes are often much more in-tuned with what should be expected. If the OP is in Canada, he/she has to respect Canada's National code as well as any other provincial code.

For example, 2.4m is the maximum allowed spacing and each anchor bolt must be embedded a minimum 90mm according to the Canadian code.

@Non Sequitur

I was not giving advice as to what Code to apply or care what jurisdiction the OP is in.

If you read my posts they run pretty cohesively;

The OP asked how to detail the top of the wall.  I mentioned a solid cap course.  Saint & Carrera indicated they were confused as to how you would even make the bolts work with a solid cap course or other wall reinforcing.  My response includes how it could be done utilizing standard joint locations and how these might fall within recommended minimums.  All of my posts include the words "in my area". 

However, thanks for the lesson on the Canadian Code.  You did not however cite the corresponding section relevant to my point.  The minimum bolt spacing recommended by the IBC or Canadian code(6-ft vs. 2.4m, or 8-ft), is irrelevantt.  Only the required minimum from the end of a wood sill member, with respect to bolt layout and CMU joint locations.

Don't want to get into a code debate but thought that AB's had to be 1/2" and joints are typically 3/8". Don't see how you could get enough mortar around the bold to meet uplift requirements by placing in joints.

JeromeS, perhaps I read your post(s) too quickly.

The Canadian code does not state a distance requirement from the end of sill plate. Anchoring spacing ranges from 900mm to 2.4m depending on structure and bracing reqs but I'm not going to do a detailed code review here. There might also be something in the appendices so I reserve the right to error.

A solid cap course is not common practice in my area... nor are CMU foundations because of the freeze-thaw cycle.

vertical joints in cmu's are bigger that 3/8".  there's the hole in the middle

unless you're using end-blocks, which don't have the hole thing in the middle at the ends

i <3 cmus

^curtkram

you ever seen these?

http://www.loomstudio.com/12blocks/

i have not.  can you get them somewhere and turn them into a building?  do you think the cost is reasonably close to regular CMUs?

I found them while researching materials for a museum project I worked on.  I do not remember where, if at all, I was able to source them.  They did not get included in the project. 

I call a solid cap a "bond beam". It looks like a U and you fill the block solid and place anchors in it. The anchor rods can be bent and tied to continuous rebar or you can drill holes and drop the anchors in epoxy and then fill the bond beam..................did this in a conversion of a 1940 beach house built by a drunk dutch boatman, not kidding, not a single 90 degree corner. We found cans of beer in practically every course of the old cmu.......... We added a floor and a roof that would count as a floor (30x70 of useable space). The local engineer and townie boys wanted us to drill 66 helical piles. Instead we poured 13 - 5x5x2 footings under the old buildings existing footings. We drilled holes through the existing footings to tie our 5x5 footings into the existing footing. Then we installed (4) #5 rebar full height and poured the existing CMU walls over the 5x5 locations full (5000 psi on everything). Imagine columns in the existing block wall. We framed a house within the block house and installed the bond beams at top to support the new floor and roof as if it were the foundation........the house is located in Ortley Beach, NJ. It stood like a fort in Hurricane Sandy. Only issue for client, a boat ended up in his swimming pool.....we did all this because we grandfathered his footprint in which would have never been approvable based on the current zoning........if you ever go to Seaside,NJ you can see the house from the bridge over Barnegat Bay....and I made sure the client could sit on his couch and view through all glass at porch down his 200 foot dock and see you crossing the bridge.

curtkram -- your pic of CMU's missed the point.  Jerome was suggesting using solid blocks as a "cap course" beneath the mud sill.  Thus Carrera's post re: 1/2" AB in a 3/8" joint.

The point of my question runs more toward asking what could possibly be the point of placing a solid block atop the wall?  You've then created a problem for no reason -- you have to work around the block to connect the sill plate to the top of the wall.

And this part:  "You could even drill and epoxy if you wanted to..." is a code violation.

I know what a bond beam is, but like I said, I never had call to use one on a house.  I'm a bit south of you, Cumberland, Atlantic / Cape May county area.

Do you have pictures of what you did with the new/old footings?  I'd like to see this... (thread hi-jacking in progress.)

Saint see my post. It's a commercial method but could be useful in house construction as we did. Note: we extended the existing CMU walls of old house up to 12 feet above grade, so a bond beam acting like rim joists was needed........I would not place solid blocks even if you planned on drilling and installing anchors with epoxy (Hilti). What you have is a separated top course structurally from the wall and I wouldn't recommend it.