Damp and Timber conmen.

[dann09]

On friday i looked at a pre-1914 terraced house with a fine stock brick frontage. The property was a rental and the distant landlord had accepted various reports and inspections in good faith. We were called in to provide a builders estimated inspection of general defects.

At the front bay there were four levels of different DPC injection holes - every time the house was sold a new surveyor called for a new "specialist" Damp and Timber report. And the D&T companies, good chaps, complied by reporting the same old rubbish every time - i have a friend live next door who observed their antics.

Each company came and, perhaps to show willing, drilled and injected one course of brick above the last drilled course. No surveyor, apparently, thought it worth noting or remarking.

The public have been fooled, the lovely old face brick is ruined and looks rubbish, and the interior damp is still there.

 

[joe-90]

Why are they drilling the brick these days?

 

[dann09]

1. Because injecting under pressure is still an approved method. Approved, meaning the mickey mouse associations that from time to time get themselves to the top of the greasy pole of Building Soc. "approvers" list.

2. AAMOF: Drilling brickwork rather than beds is a more effective method of pressure treating.

3. Using other methods might suit others, and they might be well satisfied with the results - i was taught to inject, and FWIW have found it best practice. But it's a last resort.

 

[gregers]

i too was taught to drill the bricks,i personally think that the spirit based fluid was also better in repelling any moisture and when the customer saw a dark band round there property they were happy,rather then to explain that the wall i had just injected with water based fluid under 140 odd psi HAD really been done.

ive come across something very similar where i work,1 of there properties had 2 chemical dpc installed and an attempt to install a new physical dpc.all had failed.
i opened up all the cavities and they were full up with crud that had been there for yonks,so yes it was rising but it was also penetrating,i installed a new chemical 1 once everything was cleared then re-plastered and havnt been back to that property for any problems for about 12 years now.

 

[dann09]

gregors,

Agreed, that the solvent fluid was the best for the job in hand, but terrible for the environment. Plus, it was pretty dangerous/flammable. More than one operator set the house or himself on fire.

Quite a few authorities disagree about drilling the bricks, they claim "always drill the beds". Yes, fine in theory, but how often have we seen bricks "tipped" ( or scrape pointed ) at the head/perp, and laid on strings of mortar.
I tried injecting beds for a while and sprayed gallons of fluid into the cavities - ie. there was no bed there worth speaking of. In addition, there was always the possibility of blowing out the back of the bed with the loom injection pressure.

 

[joe-90]

Funnily enough the house down the road from me had all its windows blown out the day after the stuff was injected.

 

[gregers]

i used to smoke while i was installing it when i could get away with it,worst thing that ever happened to me was when 1 of the pipes flipped out and sprayed me with a load of water based and burnt the insides of my eye lids,THAT FOOKING HURT.

ive also used the transfusion method,that was a good en.
and the 1 where you drill through the bed or the brick at 45 degrees,high pressure,low pressure.and synthapruff 3 coats last coat blinded.
always wondered why the relevant body didnt just say 'THIS METHOD is the one we recommend and thats it,rather then ALL the different methods all being backed by the same governing body.well i do know its all about the money.