Fire damaged brick (soot)

[cjs]

Hi guys
iv been and had a look at a fire damaged garage today,and have been asked to crack stitch repair 10 lm of cracks and then to k rend it,but it's only two elevations of the garage that they want done as it's only these that have been effected.
my only issue with it is that the two elevations have got soot stained over say 25% of them,is there some sort of sealer I can put over the area?would this cause any problems in the future if not treated first? Or will it be ok with just a backing coat over it and then top coated?
any of your input would help cheers guys

 

[malc]

i would fit building paper and rib lath, after i had carried out the stitch repair, to the whole wall. soot will only bleed through and there will be keying problems.

 

[superspread]

You could try jet washing first if not as Malc says

 

[church]

stabilex stops soot bleed