Stained Concrete—Protecting the slab
Do not write on slab with anything other than pencil. Framers are to use blue chalk only. The following are examples of what may penetrate and permanently stain the slab - red chalk, wax pencils, adhesives (tape), PVC primer / glue, primers, paint, caulk, flux, oils, gas, grease, liquid nail, silicone, food, coke, coffee, (other beverages included), metals left on slab can leave rust and oil marks (nails, angle iron, etc.). When ladders are being used on slab, the feet of the ladder should be wrapped or capped to keep from scarring and marking the slab. Do not set buckets or cans of anything directly on slab. Liquids and gels are our enemy. Slab should be cleaned daily. Plywood, stacked lumber, sawdust, insulation board, pressboard, polyethylene (plastic) can draw moisture from slab and cause patterned water stains to slab. Wall plates for doorways and cased openings need to be cut out early in framing process. Do not anchor to slab as the divots can be patched but will not match perfectly.

Concrete Sub Contractor
Under slab Vapor Barrier / Retarder (10 or 15 mil Polyethylene) to be placed before concrete slab being poured. Vapor barriers can be purchased at most concrete supply stores. All beams should be wrapped and all tears must be repaired prior to placing concrete slab. Preferably use minimum five-sack mix (3000 psi). Do not use surface curing compounds, retarders or chloride accelerators. Do not use fly-ash below 80F. Use no more than 15% fly-ash above 80F. Do not use fiberglass mesh or fibers in concrete mix. Do not walk on slab before surface is dry to avoid footprints. Keep trash from blades to prevent swirl marks. It is important to finish with hand tools around plumbing, risers, floor outlets, or any other areas not accessible by the machine. Blend the areas at the edge of the slab. If the finish is smoother in the center and rougher at the edges there will be a noticeable difference of color tones in these areas.

Interior Applications
The slab should be power trowelled by machine to a smooth finish. The concrete finishers can burn swirls to create a marble-like finish. Try to achieve a consistent / semi-consistent finish over complete area to be stained. Do not have one area super slick and an adjoining area semi-rough. Consistency is the key to a beautiful end product.

Exterior Applications
To achieve a slip resistant, limestone-like finish, the concrete finishers can apply a heavy rock salt finish. Also, a light broom finish can be applied to achieve slip resistance.

The floors should be clean and the room empty, with absolutely nothing on the floors prior to the arrival of our crew. Our fees do not include removing paper, moving furniture, equipment, fixtures, building materials, etc… Additional moving and cleaning will be charged as additional labor.

Application Schedule
Scoring should be done as soon as framing is finished. We will come back to stain and pre-finish immediately after dry in before mechanical, insulation, drywall, or masonry. We will need water on-site. Area should be covered after a minimum of 48 hours of receiving pre-finish. We suggest covering to be with single faced cardboard(smooth side up) overlapped and taped at the seams. DO NOT TAPE TO THE FLOOR. You can find the rolls cardboard at ECONO-BOX,  or Cornerstone Concrete Stain( all in Austin, Tx.) We will cover for an additional charge. We will return after final cleaning to apply the final finish. We are not a cleaning crew therefore all paint, mud, spills, etc… must be cleaned or scraped before we arrive to avoid incurring additional costs.

FLATWORK SPECIFICATIONS FOR

POLISHED CONCRETE

Polished Concrete Guidelines

The instructions and advice given here will help to ensure your polished concrete floor will look its best. These guide line will help insure customer expectations are met and we all get our retainage

Sub grade (Recommend laser grading)

• To minimize cracking caused by restricting movement, care should be taken to tamp and fine grade the sub grade as flat as the finished concrete on the surface to insure uniform thickness and the least resistance to friction as the slab contracts and expands during thermal temperature changes. This will reduce the reflective cracking cause by differential sub grade restraints. This will also reduce surface defects caused by bleed water pooling in low spots on the vapor barrier during the plastic state and excessive water and trash rising to the surface during hydration stage causing surface blemishes that cannot be fixed by the polishing contractor

Vapor Barrier

• An Under-Slab Vapor or Moisture Barrier should be used to prevent rising moisture from affecting your floors and maintaining a healthier establishment. Under-Slab Vapor Barrier material in 15 mil Polyethylene should be placed with the seams and penetrations taped before the concrete slab is poured and turned down in the footing.

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Mix Design

• Concrete Mixture shall be non-air entrained and Minimum 3500 PSI or higher.
• Mix should be designed at a .45 water cement ratio
• The mix shall be designed as a total gradation mix with a minimum of three aggregates fine, intermediate, large
• Any admixtures, plasticizers, slag, fly ash or anything taking the place of Portland-based cement shall not exceed 20%. * a straight cement mix is recommended
• The cement shall be Portland cement type I conforming to ASTM C 150.
• Maintain concrete temperature below 85 degrees. Keep concrete cool and moist as long as possible. Decrease the rate of hydration and drying to minimize cracking.
• Architect must approve all mix designs
• If integral color is used the minimum batch size should never be smaller than 3 cubic yards.
• Use same source for cement, aggregates, and pozzolans throughout the job.
• Monitor and control incoming material consistency. Do not use calcium chloride based admixtures. Non-chloride admixtures may be used.
• Wash out all drums before loading. Ready-mix supplier shall maintain a 5” inch slump +/- 1/2”. Obtain approval from Owner’s Authorized Representative if slump is outside these parameters. Minimize driver added water to maintain a 5” slump at point of discharge with out compromising a .45 water content ratio.

Concrete Placement

• . Place concrete with 5” slump at point of discharge, *strike off with laser screed, bull float 90 degrees to screeds pull direction, 10’ check rod is preferred over the bull float, if not available the bull float shall be 6’ in length or larger, smaller bull floats are to be used on sloped area’s, vibrate & consolidate, level to the proper elevation.

Edges

• When placing edges use a 3’ metal or wooden 2x 4 screed and run parallel with form or edge after initial screed and before floating.
• Hand floating shall be parallel to edge and done in 2’ increments to avoid lifting or depressing edges. Do not reach out beyond 2’ of edge with hand tools or float in a fan direction pulling excessive mud to the forms

Machine Floating

·       Machine Floating with pans shall begin after placement when concretes psi is sufficient to operate with out causing excessive mortar or ridges and little or no bleed water is present.

·       Slab shall be checked and re-straightened with 10’ or larger highway straight edge or bump cutter to ensure FF’s are met.

Machined Edges

• When using pans it is best to over run the formed edge by 5”

• Machined edges (walk behind) if walk behinds are used it is preferred to have pans for floating. The first pass along the edges shall be with the left side of the machine which is referred to as the cutting side. This will pull the high concrete away from the edges first. The second pass shall be on the right side of the machine which is referred to as the fill side to fill the low spots.
• Riding trowels are to be used in the same manner as the walk behind.
• The cut side of the machine is the rear
• The fill side of the machine is the front

Troweling

·       Troweling shall begin after the surface has received a 2 pan float finish. Concrete finish floors shall have a 3 pass non burned steel troweled finish; the use of plastic trowel blades will help prevent burning the aggregate. The slab drying must proceed naturally and must not be hastened by the dusting on of dry cement or sand. Lightly tool or machine all edges at construction joints and exercise care that slab edges are not depressed or chattered along bulkheads, formed edges, columns, and pipes during finishing operations, particularly hand troweling.

Local Flatness/Levelness: Except as set forth in Paragraph D below, the Random Traffic Floor shall conform to the following minimum F‑number requirements:

Floor Flatness Number: F_F

Specified Overall Value = 50

Minimum Local Value = 35

Floor Levelness Number: F_L

Specified Overall Value = 30

Minimum Local Value = 20

* Preferred strike off method: Somero S 240 Laser Screed or larger.

* If hand screed is used: Strike off with vibrating screed, using a rail system with set elevations, Slab must be bump cut with 10’ or 12’ Hwy straight edge during pan float finish in 2 directions to increase FF numbers and reduce wave index.

General Conformity to Design Grade: Except as set forth in Paragraph D  below, the entire Random Traffic Floor shall fall within +-  3/4″ of  its specified elevation.

Exceptions: Both the overall and minimum local FL levelness tolerances set forth in Local Flatness/Levelness above shall not apply to any Random Traffic Slab that is to be inclined or cambered.  Likewise, no FL levelness tolerances will be applied to any unshored elevated construction.  The general conformity to design grade tolerance set forth in General Conformity to Design Grade above will apply to unshored elevated slab constructions, but in all such cases, the tolerance will be increased to  + -  1‑1/2″.

FF/FL Testing: All floor flatness, levelness, and grade conformity tests shall be made (at the Owner’s expense) on each newly installed Random Traffic Slab within 8 hours after completion of the final troweling operation. FF and FL tests shall be made by a factory certified technician in accordance with ASTM E1155 (latest revision) using an “F-Meter”.  Grade conformity tests shall be made using an optical or laser level.  Results of all floor tolerance tests - including a formal notice of acceptance or rejec­tion of the work ‑ shall be provided to the polishing contractor within 12 hours after testing.  Failure to adhere to the testing and reporting requirements set forth in this paragraph shall constitute de facto acceptance of the work.

·       NOTE: Weekends and holidays shall be ignored when computing specified testing and reporting deadlines.

Remedy for Out‑of‑Tolerance Work:

 The entire Random Traffic Floor shall be subdivided into Minimum Local Floor Sections bounded either by the column and half‑column lines, or the construction and control joints, whichever subdivision yields the smaller areas.

All Minimum Local Floor Sections measuring at or above the specified MLFF and MLFL numbers shall be accepted for F-number compliance as constructed. All Minimum Local Floor Sections which fail to meet or exceed both specified minimum local F-numbers shall be removed and replaced (in the case of slabs-on-grade), or ground and/or retopped (in the case of elevated slabs). No remedies for defective Minimum Local Floor Sections other than removal and replacement of slabs-on-grade, and grinding and/or retopping of elevated slabs will be permitted.

If the entire Random Traffic Floor, when completed, fails to meet or exceed both the specified OAFF-number and OAFL-number, then the contractor shall rebate to the owner an amount equal to:

$1.00 x (aggregate sq. ft. measuring below Specified OAFF) *  

                    (Specified OAFF / Measured OAFF) 

                                               Or

$1.00 x (aggregate sq. ft. measuring below Specified OAFL)   *

                    (Specified OAFL / Measured OAFL)

Whichever is the greater amount 

Finish needs to be uniform in color and levelness with no trowel marks, foot prints or depressions from hand tools, knee board ECT… Concrete to be placed in accordance with ACI 302 1R 04 Class 5 floor

Concrete to be finished in accordance with ACI 117

Floor shall be tested in accordance with ASTM E 1155 The polished concrete contractor shall be included in distribution of reports and receive one copy of the FF/FL test results within 12 days of actual testing.

Saw Cutting

Based on independent studies we recommend saw cutting with Soff Cut saw ASAP without raveling edges or dislodging aggregates. We recommend the following based on slab thickness to help minimize slab curling and panel cracking.

• 4” thick to be cut at 10’ OC EW
• 6” thick to be cut at 12’ OC EW
• 8” thick to be cut at 15’ OC EW

* All re-entrant corners should have rebar inset & be cut 50% of the slab depth to reduce cracks from internal pressure

Panels should be kept as square as possible and should be approved by architect.

Curing

•  Wet curing is preferred to dam exterior edges and flood slab or run sprinkler hoses to overlap so slab has no dry spots, but if this cannot be achieved, the use of blankets is preferred; blankets must be pulled 5 days before polishing use a dissipating or water based cure and seal. Do not use a densifier/Hardener material.
• Concrete shall be cured a minimum of 28 days before Diamond Polishing.
• Application shall take place prior to fixture and trim installation and/or substantial completion.
• Polished area should be closed to traffic during Diamond Polishing.

Slab Protection

     The floor should be protected from the following:  

·       Silicone chalks should NOT be used if at all possible. The RED and yellow chalks are PERMANENT DYES. RED Chalk, black markers, wax pencils should NOT be used for framing. White or Blue chalks are OK.  Do not over mark for the framing.  Do NOT use silicone sprays to “Hold” the lines.  The sprays repel the stain and leave harsh, permanent scars on the floor.

·       Do not use , Tape, Glue, Solvents, Pine-Sol, Varnish, Non Breathing Plastics, Liquid Nail, Silicone, Plastics, Nails,  Plumbers Glue, Foam Insulation, Bond Release Agents, Flux, Oils, Grease, Polyurethane, Paint, Markers (framers often write dimensions of doorways in marker on the slab.  Ask them to make that note on the wood framing the doorway), Grease Sticks, Spray Paints, Crayons, Muriatic Acid, and other chemicals both before and after staining

Do not allow to spill or sit on floor

·       It is important that wood, sheet goods, insulation boards, plywood, press board, drywall, sections of framing and the like not lay on the slab for extended periods of time.  They can transfer resins and tannins into the slab.  This will alter the moisture content in the slab which leaves a pattern in the finished floor.  Cardboard should be placed between the slab and the stacked material to minimize any unwanted transfers. Also Food, Beverages, Oil, Glass, Metal, Paint, Caulk, or Primers

Be sure to check lifts tires for nails and screws, diaper all equipment from oil and grease drips, don’t allow pipe cutting equipment on slab

After Polish Protection

•  It is extremely important that you do not tape the floor!  When covering the floor, overlap sheets tape the first sheet to the wall then overlap the second sheet to the first and tape it to the paper.  DO NOT TAPE TO THE FLOOR.  Duct Tape, Masking Tape, Packaging Tape, Strap Tape, Blue Tape, Green Tape, and Electrical Tape there are NO exceptions.  The tape alters the natural curing process and transfers chemicals to and from the slab.  Tape, Plastics and other Adhesives can contribute to Plasticizer Migration.   This WILL SHOW in the finished product.