Victorian-house.co.uk   

 

   

  HOME            FEATURES          PLANNING          B.REGS          USEFUL LINKS         LEGAL & TECH HELP

                    

   The Haynes Victorian House Manual  updates

     

" When Ian MacMillan and I wrote the Haynes manual in 2005, some less common Victorian house defects could not be covered in great detail, as space was inevitably limited. Some issues likely to be of interest only to relatively few home owners were only touched on briefly.  However, as web space knows no such restrictions, we thought it might be a good idea to elaborate.. Also, since publication, we have received some interesting photos showing Victorian properties exhibiting perplexing defects -  some of these  are now published below."

   Ian Alistair Rock, author

 1. Got that sinking feeling? -  maybe it's down to the cellar

 2. Bulging walls ?  dodgy brickwork ?

 3. Vic bricks

 4. Thomas Crapper - toilet hero ?

all text & images copyright


  1. Got that sinking feeling? -  maybe it's down to the cellar

This photo was sent in to our office - but no one knew the story behind it !

We reckon this property was originally built with a cellar under the front reception room and  entrance hall (i.e. the left half of the picture above). But basements of this age tended to be built under only part of the house - rarely extending to the full 'footprint' of the ground floor rooms above. So the rear or side half the house may have no basement beneath it.

So what's the problem? It's all a matter of different foundation depths. The relatively deep basement means that part of the house is blessed with substantial foundations (for a Victorian house), but the non-basement part may only have the usual under-endowed footings, perhaps only 400mm deep (compared to at least 1.2m typically required today).

Result?  In poor ground conditions (shrinkable clay,  nearby trees etc) the shallow part of the house may sink, with the basement part standing resolutely still, causing structural movement in the form of 'V' shaped cracking. As if that wasn't worrying enough, the sinking rear wall may then  cause the sewer pipe (projecting out to the back garden) to crack, and the ground near the rear wall footings to become saturated.  Of course the soggy ground puts up even less resistance, inviting the building above to carry on sinking.

In some parts of the country (e.g. a number of London suburbs) semi detached houses were sometimes built with small cellars that are only about half the width of each property,  next to their side walls. So this outer half of the house has deeper cellar foundations, compared to the much shallower foundations to the party wall.  You've guessed it - the party wall may now have sunk, causing the floors to slope down towards the party wall. You may notice the roof has also have moved in this general direction, and the main walls show similar signs, with sloping window sills and brick courses.

In terraces, this can sometimes happen in reverse - e.g. where small cellars were constructed below the front reception room, but did not extend as far as below the entrance hall. Where cellars were built next to alternate party walls this can cause a terrace of such houses to exhibit periodic 'sagging',  where the houses in the terrace have settled at sideways angles.

This is all down to our old friend  'differential movement'  - the golden rule is that foundations taking similar loads should be built to the same depth - otherwise the walls may move at different rates causing settlement and cracking  - something you need to be aware of when building an extension - see www.home-extension.co.uk

This is also why it's not unusual to see fractures in the brickwork to bay windows and rear additions where they meet the main house (or at a weak point near door or window openings) - if the builders skimped on foundations. It can even tilt the whole house.

The good news is, this needn't be a major problem. Movement may have taken place long ago, often within a few years of construction,  and may well have stabiliased.

(many thanks to John Brailsford FRICS)


 

2.  Bulging walls ?

Builders' dodges - using the cheapest possible materials and then covering them up quick -  were  widespread in Victorian times, especially in smaller, less expensive houses.  In the manual we touched briefly on the subjects of walls containing  'bonding timbers', small pieces of wood inserted into adjoining walls in a vain effort to hold them together.

We also mentioned  'sham solid'  construction, where apparently solid walls were actually constructed with virtually independent outer and inner 'skins'. A bit like cavity walls, but without the cavity.

To save money, good quality brickwork laid with attractively thin mortar joints on the outer face might conceal cheap underburned 'place bricks'  on the inner face, roughly laid with fat joints by unskilled labour. As a result, the brick courses in the two 'leaves'  would not coincide, causing problems holding them together.  The use of  'bonding timbers'  bedded in the mortar to tie the 2 adjoining walls together was a short term 'solution', since pieces of wood positioned within damp outer walls will inevitably have rotted by now, quite possibly risking destabilising the wall.  The trick was to then to conceal the crime and make the wall look well bonded. So the brick 'headers' that are normally laid across the wall, holding it together, might first be snapped in half by the bricklayers so the outer facing wall looked authentic.

Sometimes the 'backing skin' was erected first, by unskilled apprentices along with the party walls,  in order to get a weathertight 'shell' in place as soon as possible. Pockets would be left in this inner skin for the headers from the outer facing wall to slot into later. But when the time came, this could prove problematic.

Worse,  this  inner leaf of soft, poor quality bricks  was likely to be carrying most of the loading from the floors above.  And cheap, under-fired bricks are likely to deform under stress,  shearing any of the few bonding header bricks that were properly built in. Being virtually unrestrained, the outer wall would now be free to  bulge out.  Walls in this condition will normally need complete rebuilding.

Similarly,  many stone walls are of 'compound construction' - an expensive stone outer facing wall with cheap brickwork or rubble stone backing. But this is less of a problem as rubble walls are not easily built less than 450mm (18in) thickness which is relatively stable. Sometimes the cavity between the outer stone leaf and the inner leaf was filled with small stone chippings and chuncks of broken stone.

 


3. Vic bricks

It's well known that builders normally tried to use reasonable quality local 'facing bricks' for visually prominent front elevations. But money could be saved by employing lower quality 'common bricks' for less noticeable side and rear walls. By the 20th century 'commons'  would increasingly be low cost manufactured 'flettons' or perhaps blotchy pink 'Cheshires'.

Cheapest of all were the underburned 'rejects' known as 'place bricks'. These were uneven and soft and widely used for non-load bearing partitions. It was not unusual to find them also in load bearing party walls - in fact anywhere they could be covered over with plaster and swiftly forgotton. At worst this may include the inner brickwork to main walls - which unfortunately (see above) take much of the loading from the floors and roof.

As noted in the Haynes manual, brick sizes were fairly inconsistent until the 20th century - if there was a standard format it was probably  9in long x 4in wide x 2.5in high.

Modern bricks are graded for frost resistance and salt content. Handmade Victorian bricks weren't - and consequently are often very vulnerable to frost attack when damp. That other 'brick killer' - sulphate attack - where the mortar reacts with sulphate salts (often contained in the bricks) can cause expansion, 'jacking up' the brickwork. Fortunately, this is more  common where portland cement was employed, rather than the lime mortar typical of the Victorian/Edwardian period.

Repointing

The important thing to remember when repointing mortar joints is that the mortar must always be weaker than the masonry. Rain absorbed by the wall will evaporate via the easiest route (normally the mortar). So normally a lime mortar mix matching the original is best. If you use hard, rigid modern cement, this is what can happen:

  

 

Over time the 'escape route'  for absorbed moisture (being damp) is likely to erode - which is why repointing is occassionally required. Use too strong a mix and the masonry becomes the escape route rather than the mortar. It's just a whole lot  easier to repoint a wall than try to repair damaged masonry!

 


4. Thomas Crapper - toilet hero?

Courtesy of the excellent and comprehensicve book  'Bogs Baths and Basins'  we have summarised some amazing facts about the British toilet pioneers whose ingenuity gave the world the flushing toilet.

 

 

 

Watch this space!

 

      HOME           ABOUT                             Copyright www.RightSurvey.co.uk    All rights reserved