Tuesday, September 27, 2005

Turning in the grave...


What we have here is the excavation for a lift pit. The pit is approximately 2 meters deep, 2 meters wide and 4 meters long, the soil here is a very heavy clay, dark brown, on top of a sandy clay. The ballast, or the layer that any foundation will be able to bear on, in this area is a river gravel. This excavation goes through a discontinued drain, and the brickwork and the fill from the drain can be seen at the end of the hole, this 'fill' is about finishes about 1.2m below the finished floor level. When I inspected this job the bottom of the hole had been trampled flat by the workers, and to confirm that they were into the gravel, I had one of the workmen dig a small trial hole about 200mm deep, to confirm that they were into the gravel.

Thursday, September 22, 2005

Room for one more?


here we go down another hole, this one again is underpinning of a party wall, with an unusual, for a victorian building, proper foundations below the splayed footings of the wall, which extend about 700mm below the footings. When I say proper, it's a lot of brick and stone thrown into a trench and covered with a very weak mix of cement. This is unusual for this type of building which would normally be built straight on top of the clay. This pin is 2.4M deep, and about 1.3M square, Carl, my able assistant, models this hole perfectly!

Tuesday, September 20, 2005

Out with the new, in with the old



here's a building with an interesting history. The plaques on the wall, are Coadstone, a cement stone invented by the first woman of construction, Mary Coad, and used extensively throughout neo-classical construction, the most famous are the Lions that perch either side of the south side of Westminster Bridge. This building was described by Nicholas Pevsner as the most important building in London, not that it looks like much, but it was the source of all the coadstone decoration for all of Londons most important buildings and monuments. The Surrey canal ended at the front door of this workshop, and barges carried stone, lime and cement to the door, and carried away some of the most beautiful decorative pieces that are the real reason why Victorian architecture is remembered. On this site, buildings have stood since the 17th century, although what remains of earlier buildings is no more than the foundations. The building seems to have been knocked down and rebuilt several times, and most recently at the beginning of the 1900's, the remaining plaques, possibly apprentices pieces, have changed position many times. Up until recently the building was derelict and in danger of collapse, but the conversion of the property into residential units is nearly complete, the restoration paid for by the construction of a new block at the rear, through the old coach doors.

Wednesday, September 14, 2005

Something old, something new



So this is the choice we are making. The top photo is one of the 1960's Haygate tower blocks, of which there are five in total, which are due to be demolished. The lower image is a sample of what is to replace them. The Haygate I believe was designed and built by the GLC, the cities architects, and was to be a series of linked estates that would run from the Elephant to Peckham. The modern building is designed by Piers Gough, who up until now has been a favourite architect of mine, that is until I got to see inside one of his earlier designs, The Circle, at Tower Bridge. My problem with his current design is that it looks like a beach front hotel, something you may see in Miami, and not south London. As this is the first development in what could be an eight year long construction phase. Come back this time in ten years and see how it fits in with the new buildings, and after the facade has weathered in.

Monday, September 12, 2005

How to fill in a hole...



Remember that hole http://smellavision2.blogspot.com/2005/09/going-further-underground.html here's whats happening to it. The walls are being cast in concrete, the steel bars are formed, like the base slab, into two layers, tied together and spaced apart from the front to the back, next a board is raised to form the front of the wall, this is known as formwork, or shuttering, and is usually treated with a release agent, so that when the concrete is cast behind the formwork, when it sets the board can be reales without it sticking to the concrete.

Sunday, September 11, 2005

Up the Elephant and around the Castle


This is the heart of my community, The Elephant and Castle shopping centre. It just so happens that it is seen as a blot on the landscape, and is due for demolition, assuming that enough money is left over from building the Olympic centre, then the redevelopment of the E&C is due to go ahead. Contractors are nominated in December 05, so some more news soon! The red building is the shopping centre, with a civil service office block above it, behind these buildings is the railway tracks, and just beyond that are three nine storey residential blocks, known as the Haygate, it is the demolition of these residential blocks that will create the most change. Currently grey concrete monstrosities, with concrete pedestrian walkways and subways, and a high level of crime, only matched by the low level of investment over the years, many of the residents have already been re-housed, some outside of the area altogether, and a large portion of what was once social housing will be laid aside for private development. As a confirmed socialist I find this aspect of the redevelopment abhorrent. When we take large strides into the future, it doesn't seem to matter who we step on.

Tuesday, September 06, 2005

It's cold up north...


This old warehouse conversion was commenced the first day I started university, back in 1994, and was recommended to me as a place to buy - I decide to stay a council tenant. Today I did a final inspection of a studio flat, that could very well have been my own flat. Not only did they guy have a wall full of the same DVD's I watch, have a bookshelf full of the same books I read, he also had original comic cels from my favorite Batman animated series, some of the comics that I collect, all the AD&D role playing books I have. This bloke could have been my twin - except for the difference in salary!

Going further underground...


Here we have the deepest hole so far, this is about 4 metres below ground level, and is part of a lift pit. Note the sheet driven piles around the edges, like large crinkled sheets of corrugated iron, these sheets are driven into the ground, usually by a pile driver and then the ground is excavated. At the base of this pit a concrete slab is about to be poured, two layers of steel bars are tied together, and spaced apart to form a raft of steel. The concrete is delivered ready mixed and poured onto the steel, and is usually vibrated into place to ensure that no voids are left. What I am checking for is that the steel sizes are as per the Engineers design details, that the steel bars are lapped well, tied together, that there are spacers (in this case steel chairs - usually plastic spacers are used), the spacers are to ensure that the concrete covers the steel by a minimum of 25mm to ensure that no water gets into the steel and causes it to rust. Basically, I was taught on my first job to ensure that the steel is free from crisp packets and cans of coke, not much else can go wrong.

Monday, September 05, 2005

Only Fools and Horses...


...Work. It seems regeneration works too. Here we have the new public square in peckham, viewed from the Surrey Canal path, now grassed and treelined cycle path, to the left the Sterling prize winning Peckham Library, designed by Will Alsop, to the right the Southwark Building Design Services, Peckham Pulse, a health and fitness centre and the third side of the square is bound by the Peckham Arch. Home this year to the Peckham Festival, and every Sunday to a farmers market - where I bought the beef for this weeks Sunday roast!

Friday, September 02, 2005

How many holes does it take to fill the Albert Hall?



4000.

That's according to the Beatles, and I think they were comparing it to Blackburn, Lancashire. So we finally get around to the subject of holes. We've seen quite a few buildings go up, but here lies the secret of a good building. Firm foundations. Many of the jobs I undertake are to support buildings that have begun to move, this picture shows (and not very clearly, but squint and persevere) a 1.5m deep concrete slab, or 'pin', sitting under a 450mm wide brick footing, a footing is where the bricks of the wall are splayed out, usually in three or four courses, to help spread the loads that are transferred down the wall from the floors and the roof above it, onto the soil below. In this case it is onto clay. London Clay is one of the better soils for small buildings to bear onto, it is very firm, and usually to a 3m depth. Of course modern design would not be satisfied with a three storey building bearing on such shallow footings, here they are about 500mm below the level of the external ground. The wall has been moving because of an underground stream washing the clay away from under the wall, so an excavation of the clay is undertaken, in this case 1.7m deep by 600mm wide, the sides and the bottom of the pit are cleaned up, brushed down of any debris and the void is mass filled with concrete. Once this section is set, the next pin is excavated, jointed to the previous pin, and poured.