GUIDELINES FOR EVALUATING THE CONDITION OF BRICK MASONRY AND
MORTAR


CAUTION:  THIS METHOD OF CONDITION ASSESSMENT IS DESTRUCTIVE AND
SHOULD ONLY BE USED TO TEST AREAS BELIEVED TO BE DETERIORATED. 
THIS TEST SHOULD BE PERFORMED ONLY BY AN EXPERIENCED MASON.

This method of evaluation was developed by restoration architect
Max Ferro and masonry conservator Tom Russack and appeared in the
January/February 1987 issue of the old house journal.  


***MATERIALS***

-    Mason's hammer
-    Cold chisel (1/2 to 1-1/2 inches)
-    Sturdy slotted screwdriver

The deterioration of brick and mortar are evaluated by rating each
on a scale from 0 to 10 based on their level hardness or softness. 
A rating of 0 indicates severe brick and/or mortar deterioration. 
A brief description of each rating follows.


***ASSESSMENT OF BRICK***

A rating of '4' or below indicates brick in an unsalvageable
condition.  A rating between '5' and '7' indicates that some
remedial measures may need to be taken.  A rating of '10' indicates
that the brick units are in good, sound condition.


RATING    DESCRIPTION

0         Bricks are totally disintegrated.

1         Evidence of spalling at least 1/4" to 3" deep.

2         Slight erosion at corners of brick; slight powdering of
          surface when rubbed with hand or scraped with fingernail.

3         Spalling brick in layers when rubbed with hand; fragments
          do not powder.

4         Bricks can be broken by poking and jabbing with
          screwdriver; fragments are semi-hard and resemble
          compacted clay.

5         FIRST CLASS OF STABLE, STRUCTURALLY SOUND BRICK:
          Screwdriver can penetrate the brick by hand roughly 1/4"
          but brick does not crumble.

6         Screwdriver can penetrate the brick roughly 1/4", but
          ONLY with the assistance of a hammer; this may cause
          coarse jagged pieces to become dislodged.

7         Screwdriver is unable to penetrate the brick even with
          assistance from hammer but may make a slight impression
          in the surface.  There may be a slight ring or bounce as
          the screwdriver hits the surface.

8         Chisel is necessary to crack the brick.

9         Chisel is unable to make an indentation or impression in
          the brick; brick shears cleanly; brick is strong with
          crisp edges and corners.

10        A NEW BRICK:  Brick with crisp corners; chisel striking
          the surface produces a clear ringing sound.


***ASSESSMENT OF MORTAR***

A rating between '0' and '4' indicates that repointing is
necessary.  A rating between '5' and '8' indicates mortar in
satisfactory condition.  A rating of '9' or '10', indicates that
the mortar is too hard and should be replaced with a softer mortar.


RATING    DESCRIPTION

0         No evidence of mortar within at least 1-1/2" of the wall
          face.

1         Mortar crumbles when poked with finger or screwdriver;
          many surface irregularities are evident.

2         Mortar is easily removed with screwdriver, but FEW
          surface irregularities are evident in joint.

3         Mortar collapses and freely and cleanly breaks adhesion
          with brick when scored along centerline with screwdriver.

4         Slight spalling occurs at edges and corners of brick when
          mortar is scored and tapped with screwdriver.

5         Screwdriver is unable to dislodge the mortar; chisel can
          disengage and pop mortar free without damaging the brick.

6         Edges and corners of brick are slightly marred when
          mortar is scored with a chisel.

7         Hammer AND chisel are necessary in order to disengage the
          mortar; there should be little damage to the brick.

8         Several blows with hammer and chisel are required to
          break the mortar into several large pieces; bricks will
          be noticeably marred.

9         MORTAR IS STRONGER THAN THE BRICKS:  Successive blows
          with hammer and chisel crack brick.

10        MORTAR HAS HIGH PORTLAND CEMENT CONTENT:  Successive blows
          with hammer and chisel pulverizes the brickwork.

                          END OF SECTION