Method of Statement for Plastering

8/12/2019 Method of Statement for Plastering

1/6

method of statement for plastering

method of statement for plastering,Wall Plastering Tips,Plastering Techniques,Free Method Statements

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

Summary: This method of statement for plastering includes the following;

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

Internal Portland cement plaster:

External Portland Cement plaster:

Formed in Place plaster grooves in elevation:

External Formed in place decorative cornices in building elevation

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

method of statement for plastering


2/6

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

Materials for Application;

1. Portland Cement ASTM C150 Type

2. Sand Aggregate ASTM C 897 White Sand for base coat, red sand for dash coat.

3. Plastering Accessories: Metal Lath, angle beads, special pieces for internal angles and corner.

4. Fiber

5. Trial Mix

6. Details for Metal Lath Location and Installation (Typical) (Submission for Approval) (Trans.# C-0260).

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

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


3/6

1. Preparation

A. Clean the surface and remove any dust, contaminated materials on plaster bases and substrates for

direct application of plaster, removing loose material and substances that may impair the work. Form

ties and other obstruction shall be removed or trimmed back even with the surface of the solid base.

B. Dissimilar Backgrounds: where rendering is to be continued without break across joints between

dissimilar solid backgrounds which are in the same plane, cover joints with 200mm wide galvanized steel

lathing as specified & approved fixed with corrosion resistant fasteners at not more than 600mm

centers along both edges, apply mesh over electro-mechanical embedded conduits.

C. Apply forcefully dash coat on concrete and concrete masonry surfaces indicated for direct plaster

application. Dash coat is to cover full surface to be plastered and is to provide rough surface of sharp

protrusions ranging 3.0mm and 5.0mm. Dash-Coat Mix: 2 volume parts Portland cement to 3 volume

parts fine sand, 1 part bonding agent to 3 part clean water mixed to a mushy-paste consistency shall be

left untroweled, undisturbed and moist cured for at least 24 hours after application and before

plastering.

D. Install temporary grounds and screeds to ensure accurate rodding of plaster to true surfaces. Check

the straightness in each corner and add grout to hold the external corner beads in correct and internal

position to be fixed using corrosion resistant fasteners.

E. Before plastering starts, dampen, by spraying water concrete dash coat surfaces that are to receive

plaster with clean water.

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

2. Application


4/6

A. All plaster shall be prepared in a mechanical mixer mix 1:5 (1 part cement and 5 part sand) using

sufficient water to produce a workable consistency. Mix fiber 0.6 kg/m3 of the mortar or plaster by first

mixing with some water (30%). After all the ingredients have been added including the remaining mixing

water, the plaster should be mixed for a further few minutes until uniform fibre dispersion. Plaster not

used within 1.5h from start of mixing shall be discarded.

B. The second coat shall be applied with sufficient material and pressure to ensure tight contact with

dash coat.

C. The surface of the second coat shall be brought to a true, even plane with a rod or straightedge, filling

surface defects in place with plaster.

D. Applied plaster shall be floated as smooth as possible and then steel-troweled. Steel troweling shall

be delayed as long as possible and used only to eliminate the uneven points and to force aggregate

particles into the plaster surface.

E. Each plaster coat shall be applied to an entire wall or ceiling panel without interruption to avoid cold

joints and abrupt changes in the uniform appearance of succeeding coats. Wet plaster shall abut set

plaster at naturally occurring interruptions in the plane of the plaster, such as corner angles, openings

and control joints where this is possible.

F. Make internal angles and corners square.

G. Finished grooves shall be neat, of uniform width and depth, sharp straight edges and exact vertical

and horizontal lines. Elevation grooves shall be cut before plaster sets by using molded guide or wooden

strip and fixing it in temporary grout and screed. Regarding recessed, follow the procedures same as

grooves.

H. Form cornices by plastering additional coats against pre-formed wood templates fixed onto plastered

elevation. Make form wood templates to shapes, dimensions and projection indicated on drawings.

Apply additional under coats in thickness not more that 10mm until obtaining required projection. Final

finishes refer to item D.


5/6

I. Plaster should not deviate more than plus or minus 3mm in 3m from a true plane in finished plaster

surfaces, as measured by a 3-m straight edge placed in any location on surface.

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

3. Curing

A. Provide sufficient moisture in the plaster by spraying water as frequently as required at least twice

per day.

4. Cutting and Batching

A. Cut, patch, replace, repair and point up plaster as necessary to accommodate other work. Repair

cracks and indented surfaces. Repair work to eliminate blisters, buckles, check cracking, and dry out as

necessary to comply with visual effects.

B. To correct inaccuracies, dubbed out in thickness of not more than 10mm in same mix as base coat

and total thickness of

dubbing must not exceed 25mm unless otherwise approved.

In areas where thickness is more than 20mm, apply dash

keying mix before adding new layer.

C. To correct inaccuracies in beam, column together with block work, chip carefully the concrete

structures by using hammer and chisel to receive dash coat (follow the procedure in 1.C). For 25mm


6/6

thick plaster repair apply it one time as per 2.B. For 45mm thick, apply 20mm first coat and apply keying

mix before adding the new layer. Each layer must not exceed

10 mm, start again same as from 1C.

Documents

Method of Statement for Plastering