SECTION 04500

MASONRY RESTORATION AND CLEANING

PART 1 GENERAL

SECTION INCLUDES

[Water] [Steam] [Chemical] cleaning of [__________] surfaces.

Replacement of [__________] units.

[Sand blast cleaning of [__________] surfaces.]

Repointing mortar joints.

[Repair of damaged masonry.]

[Moisture repellent coating.]

RELATED SECTIONS

Section [_____-__________]: Special protection [to surrounding properties.] [________________.]

Section 01710 - Final Cleaning.

Section 03730 - Concrete Rehabilitation:	Restoration of concrete surfaces.

Section 04100 - Mortar.

Section [_____-__________]: [_______________] masonry work.

Section 07175 - Water Repellant Coatings.

Section 07900 - Joint Sealers.

Section 09900 - Painting: Repainting [__________] surfaces.

REFERENCES

ANSI A41.2 - Building Code Requirements for Reinforced Masonry.

International Masonry Industry All-Weather Council (IMIAC) - Recommended Practices and Guide Specifications for Cold Weather Masonry Construction.

SUBMITTALS

Submit [shop drawings] [and] [product data] under provisions of Section [01300.] [01340.]

Indicate on shop drawings, [setting details of [cut] [__________] stone] [details of special [brick] [__________] shapes] [special supports for the work] [________.]

Provide product data on [cleaning compounds] [cleaning solutions] [________.]

Submit drawings detailing [shoring] [bracing] [__________] and temporary or permanent support, sealed by a Professional Engineer registered in the State of [________.]

Submit samples under provisions of Section [01300.] [01340.]

Submit [two] [__________] samples of colored [mortar] [sealant] [_____ x _____] inch ([_____ x _____] mm) in size illustrating color variations anticipated.

Submit [two] [_____] samples of [brick] [stone] [__________] masonry units.

Submit manufacturers' application instructions under provisions of Section [01300.] [01340.]

QUALITY ASSURANCE

Restorer: Company with [three] [__________] years [documented] experience in masonry restoration.

****** [OR] ******

Restorer: [__________] [__________] [________.]

FIELD SAMPLES

Provide samples under provisions of Section [01300.] [01340.]

[Construct] [brick] [__________] field sample panel, [_____] inches ([_____] mm) long by [__________] inches ([_____] mm) wide, illustrating finished [wall.] [________.]

Locate [where directed.] [_________________________.]

Accepted sample may remain as part of the Work.

MOCKUP

Provide mockup of restored area of [__________] under provisions of Section [01400.] [01405.]

[Restore] [Repoint] a [4 x 4] [8 x 8] foot ([1 x 1] [2.5 x 2.5] m) wall panel using materials and methods specified.

Clean a [10 x 10] [__________] foot ([3 x 3] [_____ x _____] m) panel of wall to determine degree of cleanliness.

Repeat, using [same] [different] cleaning methods [up to [three] [__________] different panels,] until acceptable.

Acceptable panel [and method of procedure] will become the standard for Work of this Section.

PRE-INSTALLATION CONFERENCE

Convene a pre-installation conference [one] [_____] week prior to commencing work of this Section, under provisions of Section [01200.] [01210.]

Require attendance of parties directly affecting work of this Section.

Review conditions of installation, installation procedures, and coordination with related work.

DELIVERY, STORAGE, AND HANDLING

Deliver products to site under provisions of Section [01600.] [01610.]

Store and protect products under provisions of Section [01600.] [01620.]

Deliver [masonry] [stone] neatly stacked and tied on pallets. Store clear of ground and cover with waterproof covering.

Furnish [sand blasting] [acid solution] [restoration cleaner] materials in manufacturer's packaging, including instructions for use.

ENVIRONMENTAL REQUIREMENTS

Do not lay [masonry] [stonework] [__________], repoint, [calk,] wash down or wet surfaces when temperature may drop below 40 degrees F (4 degrees C) within twenty four hours.

Follow cold weather procedures in accordance with ANSI A41.2 when temperatures may drop below 40 degrees F (4 degrees C).

****** [OR] ******

Cold Weather Requirements: IMIAC - Recommended Practices and Guide Specifications for Cold Weather Masonry Construction.

Do not sandblast or use process creating dust, dirt, [or] [__________] when wind is over 10 miles/hr (4.5 m/sec).

SEQUENCING/SCHEDULING

Perform [sandblasting] [cleaning] [washing] [__________] of exterior masonry [between the hours of [7 a.m. to 11 p.m.] [________.]

Perform repointing [before] [after] cleaning.

PART 2 PRODUCTS

MANUFACTURERS

[________________________________.]

[________________________________.]

[________________________________.]

Substitutions: Under provisions of Section [01600.] [01630.]

CLEANING MATERIALS

Cleaning Agent: [Detergent] [Solvent cleaner] [Acid solution] [__________] type.

Cleaning Agent: [0.5] [0.75] [_____] lb ([227] [340] [_____] g) of [sodium hydrosulphite] [acidified sodium fluosilicate] [ammonium bifluoride] [__________] mixture to one gallon (3.8 L) of water.

Acid Solution: Clean, stain free, commercial hydrochloric (muriatic) acid, mixed one part to [10] [15] [_____] parts of potable water.

Blasting Sand:	[________________.]

MORTAR MATERIALS

Conform to requirements of Section [04100.] [__________.]

MASONRY MATERIALS

Brick:	[___________________________________.]

Stone:	[___________________________________.]

Terra Cotta: [_____________________________.]

Clay Tile:	[_______________________________.]

Block:	[___________________________________.]

PART 3 EXECUTION

EXAMINATION

Verify that surfaces to be [cleaned] [restored] are ready for work of this Section.

Beginning of installation means acceptance of existing surfaces and conditions.

PREPARATION

Protect elements surrounding the work of this Section from damage or disfiguration.

Carefully remove and store fixtures, fittings, finishing hardware, accessories [__________.]

[Close off,] [seal,] [mask,] [and] [board up] areas, materials, and surfaces not receiving work of this Section to protect from damage.

Construct [dustproof] [and] [weatherproof] partitions to close off occupied areas from work of this Section.

Protect roof membrane and flashings from damage.	Lay [1/2] [__________] inch ([13] [_____]mm) plywood on roof surfaces over full extent of work area[.] [and traffic route.]

Provide [sand] [waterproof] [__________] dams to divert flowing water to [exterior.] [floor drains.] [________.]

CLEANING EXISTING MASONRY

[High] [Medium] [Low] Pressure Steam Cleaning: Apply [_____] psi ([__________] kPa) pressure to [__________] type masonry surfaces at [__________] locations, maintaining uniform depth and surface texture throughout.

Cleaning Detergent: [Brush] [Spray] [Hand wash] clean [__________] type masonry surfaces at [__________] locations with [__________] type [detergent] in accordance with the manufacturer's instructions.

Chemical and High Pressure Steam Cleaning: [__________] psi ([__________] kPa) pressure, [__________] percent [__________] chemical solution for [__________] type masonry surfaces at [__________] locations to remove existing [__________] coating and leave surface with uniform, [natural] [__________] color and texture.

Sand Blasting: Sandblast with hard sand blown by compressed air at [_____] psi ([_____] kPa) pressure, against [__________] type surfaces at [__________] locations with [__________] type [detergent] in accordance with the manufacturer's instructions.

High Pressure Cold Water: Cold water blast with [__________] psi ([__________] kPa) pressure to [__________] type masonry surfaces, at [__________] locations, providing

uniform finish.

Wet [Sand] [Aggregate] Cleaning: [________.]

CLEANING NEW MASONRY

Verify mortar is fully set and cured.

Clean surfaces and remove large particles with wood scrapers, brass or nylon wire brushes.

Saturate masonry with clean water and flush loose mortar and dirt.

Scrub walls with [__________] type detergent solution using stiff brush.

Thoroughly rinse and wash off cleaning solution, dirt, and mortar crumbs using clean, pressurized water.

Use acid solution mixed with water in accordance with manufacturer's instructions.

Apply acid solution and scrub [__________] masonry with stiff fiber brushes. Do not scrub the mortar joints.

Protect area below cleaning operation and keep [__________] type masonry soaked with water and flushed free of acid and dissolved mortar continuously for duration of cleaning.

Before solution dries, rinse and remove acid solution and dissolved mortar, using clean, pressurized water.

RESTORATION CLEANING

Clean surfaces and remove large particles with wood scrapers or non-ferrous wire brush.

[Spray] [Brush] coat [__________] type masonry with [__________] restoration cleaner, mixed into solution [in strict accordance with manufacturer's instructions.] [identical to that required for sample area.]

Provide a second application if required by preliminary test of sample area.

Allow sufficient time for solution to remain on masonry [and agitate with soft fiber brush or sponge].

Rinse from the bottom up with potable water applied at [400] [600] [__________] psi ([2 750 [4 140] [__________] kPa) and at a rate of [4] [__________] gal/min ([16] [__________] L/min).

REBUILDING

Cut out damaged and deteriorated [masonry] [stone] [__________] with care in a manner to prevent damage to any adjacent remaining materials.

[Needle] [Shore] [Support] structure as necessary in advance of cutting out units.

Cut away loose or unsound adjoining [masonry] [mortar] [and] [stone] [as directed] [to provide firm and solid bearing for new work].

Build in [new] [reclaimed] [masonry] [stone] units following procedures for new work specified in Sections [04100] [and] [04300.] [________.]

Mortar Mix: [Colored to match existing work.] [As specified in Section 04100.]

Ensure that [anchors] [ties] [reinforcing] [stone cramps and dowels] [flashings] are correctly located and built-in.

Build-in [masonry] [stone] [__________] work to match and align with existing, with joints and coursing true and level, faces plumb and in line. Build-in all openings, accessories, and fittings.

REPOINTING

Cut out loose or disintegrated mortar in joints to a [1/2] [__________] inch ([13] [_____] mm) depth.

Utilize [hand tools.] [power tools only after test cuts determine no damage to masonry units will result.]

****** [OR] ******

Do not use power tools.

Do not damage masonry units.

When cutting is complete, remove dust and loose material [by brushing] [with water jet].

Premoisten joint and apply mortar specified in Section 04100.	Pack tightly in maximum [1/4] [____] inch ([6][____] mm) layers. Leave a smooth, compact [concave] [raked] [flush] joint.

Moist cure for [72] [_____] hours.

AGING

[Rub-in] [Dust] new [masonry] [stone] [__________] work to match, as close as possible, adjacent to original work.

Use [carbon black] [__________] in small amounts, rubbing in well with [burlap rags.] [medium bristle brush.]

After each application, dust off surplus and wash down with low pressure hose. Allow surface to dry before proceeding with succeeding applications.

Continue process until acceptance.

CLEANING

As work proceeds and on completion, remove excess mortar, droppings, smears, stains, efflorescence, or other unsightly excess resulting from the work of this Section.

Clean surrounding surfaces.

SCHEDULE

END OF SECTION