Verily  I say on to you

This is something we always run into  on masonry parapets

; and we make our decisions and recommendations

on the

A/ the porosity of the substrate ;  and its drying cycle .

B./ Access ability;

can I easily get to it for maintenance;

 or does it cost and arm and a leg ?

C / if its original ......what is the condition of allowing the coping to continue as it is ?

Despite through wall flashing below it ? i

D if  its Historic and George Washingtom slept on it after a night out with the boys  ;

what methods  should i consider for its preservation and repair ?

E/ If it rains for three days in February

;and then goes into a deep freeze for a week

how best should I interpret my options for its preservation ?

E/ If its historic and high up and (only I slept on it

after a night our with the boys ;}

 what methods

sealers ; mineral coatings ;  and historically color  matched elsto meric coatings

do to  I give myself  permission (and the owner )

 the option to consider  with such a  tight ass budget  ?

 

We just finished a large 1920 church in alabama ;

with original very large very thick  poured cast stone

copings (now through age )

very porous;and susceptible to freeze thaw ;

 that after almost 90 years

the fissures and micro cracks (although not visible from the ground );

were very active and numerous on the stone

and after a rain the substrate was  soaked and appeared to hold water for many days

as it dryed out

Having taken several days myself to dry out ; i know the feeling   .

Alabama can have very freezing weather

The copings were over 60 ft high ;

and impossible to get to without fixed scaffold ,

Visibility of them from a historic perspective was only witnessed through color and tone 

 and the rectangle thick shape that was supposed to mimic stone

  ;

Now they appeared to be a time capsule of  tar repair

There joints had all been  tarred ; which when cleaned gave a mottled appearance to the stone which no longer had much of its original color left after 90 years in the sun  

 

The church had a limited budget ;

 these stones were not coming down ;and we were not going to seal them

with something that had to be done every ten years

Over the parapet flashing was discussed ;

 but cost and looks were a consideration .

We wanted it to mimic the off white limestone that the window sills still had 

and although it can be done ; it would be challenging on flashing and cost more t&M

 

We gave samples of mineral coatings ;and elastomeric coatings which to the eye

from the ground could not be seen they had anything on them .

Using compatible patching mortars for cast stone we filled cracks ;

 and replaced friable or missing substrate.in shapes that needed it 

 The historically matched elstomeric was chosen as the best sealer

and water repellant;based on longevity and  the church budget ;

 and that it also  covered and blended over any repairs old and new  that were off color

However we  directed its use

to be  only used on the flats (surface facing upwards  )

; and only any of the returns facing the street ;

 the idea being  leaving the non visible inside roof returns

(and the underneath overhang of  coping /in shade  )    

still open to the drying air  and natural sun cycle of the exposed roof    

 

all these decisions were  case by case ;

 our rule of thumb always is that what ever method is chosen

it  has to be structurally sound and read like the original  ;

and of course  the lower you go on a building

the more challenging that concept is 

 

Had  George Washingtom slept on it ; the case most certainly would of been different ; if it were the Met or the white House  ; then the budget would have certainly  been different.

and lastly in my case ;

if my aunt had chitins

she would be my uncle   /Py