Concrete Block Walls

Depending on how the concrete-block walls are anchored to the slab, they might be subject to forklift impacts, for instance. Concrete curbs integral with the slab would help to prevent this. If the slab slopes for drainage, the tops of the curbs could be made level. If air circulation space (or fire spray space) is needed behind whatever product is stored next to the wall, the curb can be made wider than the wall, helping to ensure such air space. Finally, local construction codes may require this. I am not knowledgeable on these code aspects, but other responders are likely to give good assistance.

thanks for the relevant suggestions! Much appreciated.

How are Terrance and Philip? Hey?

??

Well, some of them, maybe.

Check out South Park.

Hello,

Are you an Architect or an Engineer? If neither, why are you designing such a structure if you have no experience doing so, as it's pretty obvious from your statements and questions????. Leave the designing to a Licensed Professional, or otherwise your building may collapse and possibly maim or kill someone!

Pursuant to your questions I offer the following advice:

It all depends on how the block courses are started along the exterior walls, especially if there are foundation walls that extend several feet (to a level somewhere below the frost line in your area) below the exterior ground surface and rest upon reinforced concrete footings. The exterior and interior block courses do not necessarily have to correspond to the top of slab elevation (interior slab on grade). What is very important is that the block course joints are identical for both exterior and interior walls, not matter if they're load bearing or not. There's several key reasons for this requirement, as follows:

1). The interior walls are properly "keyed" into the exterior walls where they meet providing structural stability laterally and longitudinally,

2). There is a continuous mortar joint at the aforementioned wall junctures, and hence continuous horizontal joint reinforcement in the horizonal block joints, and reinforcement overlapping especially at. Usually, Dur-O-Wall joint reinforcement, or it's equivalent, is installed every other block course joint. I recommend using truss type over ladder type due to higher stiffness.

3). You need to provide a continuous CMU bond beam that is properly reinforced and fille with concrete at the top of the CMU walls.

Again, please SERIOUSLY heed my advice above, or you will be liable in a court of law for your own actions.

all I asked for was the pros and cons of using a curb (or not) for interior concrete block walls!

Have a Prozac.

Hi Doogleass,

My last construction job consisted of 30,000+ block (USAF Sports and Fitness Center) and was built to Builiding Code Standards (UBC). Which Code are you using in the design? Is it a Public Building? Are design specs and drawings certified by a licenced structural engineer or architect? Load bearing walls may have a thickened slab at load bearing walls (depending on soil conditions!). A soils engeineer will determine the type of concrete foundation (depth or type) depending on soils conditions.

All block walls are usually constructed with: 1. No.4 rebars imbedded vertically at 4 foot on centers into the slab, and at ends of door openings. 2. CMU's lay on a finished slab, and then proceed in four foot sections, and horizontal reinforcement is inserted on grooved block (horizontally). 3. The verticle rebar is continous from slab dowels and carried to roof beam elevation by splicing the bar, and then both horizontal and verticle cells are grout filled, using 1/2 inch rock and seven sack mix. (pump mix).

All block walls should be tied to a slab by rebar at four foot centers as a structural stability requirement.

DRS Company

to clarify to my original enquiry, if I can summ it up: pros and cons of curb no curb.

I am quite familiar with CMU construction and reinforcement and really not at all interested in grout mix design. Thanks anyway for your suggestions.

Hi Inginere,

Some thing else to consider when considering an interior block wall?

1. If you have a sloping slab (as mentioned), you may necessarily have to "stair-step" the first block course to keep the wall plumb (verticle in the Z-axis). Then you would have to insert verticle dowels into the (existing) slab, and may be form for "stair-steps".

2. Some walls may rise to roof level and may be tied to or support roof steel.

3. Some walls may have to be fire rated (so consturction must meet fire code requirements).

These are important structural considerations, and it is good to be at least a licensed contractor (or work with one), so you know when to go to a structural engineer for wisdom and design experience.

Just want to be helpful.

DRS

performance@tularosa.net

Tularosa, New Mexico

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"An ounce of prevention is worth a pound of cure." Ben Franklin

Hello and welcome Ingenere,

On the load baring walls, once these walls are built and the building in use, often these 'load baring walls, may be used in turn to hold or support other machines and or other structures. Because of this likely use, I would use appropriate foundation trenches for each supporting structure, whether that be the bottom end of a beam or the whole length of a supporting wall.

It is easier and more practical to pour each 'room' or 'divided space' floor separately. That way the stresses of the 'continued' floor into another, area is not transferred.It is also then possible to use a tighter slump or not in each area depending upon it planned use. For a machine shop it would perhaps be a thicker stronger floor compared to one 'next to it' which is for packaging storage only?

Build the foundation so that after a single layer of bricks or concrete blocks, the floor is level with the top of these first courses. Then use the appropriate damp-proofing and a 1000 or perhaps 2000 grade plastic sheet to cover the whole floor area before the pouring of the concrete floor.

The slab can be built directly with concrete blocks, but, if for whatever reason there is movement of the slab, say it cracks, then any walls running over than crack will possibly be unsafe. That is why I say use the trench foundation method.

I wonder why you would want a curb other than to perhaps prevent rain or other water getting on the floor from outside, or from another higher area in the building structure?

Please see the sites below.

1. Housing and Building Codes: Dry (Water and Moisture Control)Your browser does not support script ... According to the Asthma Regional Coordinating Council of New England, walls should be designed ... Unless waterproofed, foundation walls that retain earth and enclose habitable space .... from entering the building or becoming trapped in the foundation walls or floor slab). ...
   www.afhh.org/aa/aa_housing_codes_dry.htm - Cached - Similar -
2. Green Schools: Attributes for Health and LearningAsthma affects 8 to 10 percent of the population and even larger proportions ..... Below-grade building assemblies like foundation walls, footings, and slabs .... Moist air also leaks into basements through floor and slab perimeters, wall .... inside the building by students, teachers, support staff, or visitors. ...
   books.nap.edu/openbook.php?record_id=11756&page... - Cached - Similar -
3. Welcome to House-Building.com... asthma, or respiratory illness this information is absolutely essential. ... Some Useful Links Crawl Space vs. Slab Foundation ... no interest payments during the building process, and construction support while you build. ... There are advantages and disadvantages for having a poured concrete wall vs. a cement ...
   www.house-building.com/newsletters/newsletter_april05.html - Cached - Similar -
4. Toxic Mold Testing and Sampling5 May 2009 ... Allergy, Asthma, & Sinusitis allergy-asthma-sinusitis.com ... intrusion into the building's foundation, concrete slabs, and basement walls]? ...
   www.allergy-asthma-sinusitis.com/toxic%20mold%20testing%20&%20sampling.htm - Cached - Similar -
5. The New England Asthma Regional Council: Healthy and Affordable ...Part 2: Building Housing That Minimizes Asthma Triggers – Technical Modules .... breaks on top of new concrete footings and the perimeter foundation wall (e.g., ... perforated pipe under floor slab level piped to sump or daylight. ...
   www.asthmaregionalcouncil.org/about/housingtraining.html - Similar -
6. Building Science Consulting - Designs That Work - Cold Climate ...Foundation: Slab-on-grade; Above Grade Walls: Wood frame .... require humidity control (and high-efficiency air filtration) for asthma trigger control. ...
   www.buildingscience.info/designsthatwork/cold/.../minneapolis.htm - Similar -

take care.

thanks for the wealth of information and recommendations!

Hi Ingenere,

I appreciate your reply post with your thanks!

Were you able to use one of the links or did you just read for general info?

Why are you 'designing' this,.....IF....you have to ask this basic question....??? Get an engineer!