Cracked stone door frame (jamb?)

[drpepe]

Hi all,

We’ve just moved house and the front door jamb has an impressive crack as pictured.

Can anyone advise on whether this would be considered an urgent (structural) repair and whether this would be one for a regular builder or someone more specialised in sandstone like a stonemason?

edit: nothing untoward visible inside but is largely concealed by plastic and a meter cupboard. The door opens , closes and locks perfectly normally.

many thanks

 

[KenGMac]

drpepe, good evening.

Not convinced that that "stone" is indeed a Sandstone?

Could be a man made faced Concrete? if so the embedded reinforcing may ??? be corroding??

Ken.

 

[drpepe]

drpepe, good evening.

Not convinced that that "stone" is indeed a Sandstone?

Could be a man made faced Concrete? if so the embedded reinforcing may ??? be corroding??

Ken.

Thanks Ken. No doubt you are probably correct. There are a number of 1930s semi detached houses in the street with an identical design.

Any idea how to investigate and/or repair this? Or who would be qualified to advise?

 

[KenGMac]

drpepe, good evening, again.

What is possibly happening is that your door jamb is man made concrete with a brushed or other intended finish.

To stabilise this piece of [what is in effect Concrete] there is [generally] a single reinforcement bar embedded into the Concrete. this embedded reinforcing is a steel bar.

Back in the day, when Concrete was being first explored and used more and more the need for the reinforcing bar to be embedded a minimum of [generally] 50+ mm. was not really fully appreciated, as far as the longevity of the component was concerned.

What may?? have happened to your door jamb is that the embedded steel reinforcing has corroded, this corrosion produces rust, over time the rusts expansion simply cracks the surrounding Concrete, expanding rust can exert a truly massive force.

If the reinforcing bar were to protrude down to that joint, there is a perfect path for rain to get at the bar and the corrosion starts.

As for repair???

Remove the damaged area, "get at" the rusting bar, clean it of, thoroughly, back to shiny bright steel that is the easy bit, coat the bar with an impervious layer of [say] epoxy resin?to keep the water away.

Re-build the mullion, but??? how do you replicate the colour / texture match. This is the big, highly visual problem.

Also if you do not remove all the rust then the bar will continue to corrode and somewhere down the line here we go again?

Ken.