A Little bit about me...

I'm a Structural Engineer, specialising in conservation, at Hurst Peirce + Malcolm in London. I don't wear tweeds, am not particularly "cultured" and I'm not that old, but I do care passionately about the conservation of old buildings. I am a Chartered Structural Engineer, a member of The SPAB (formerly on the founding committee of the reborn Berks, Bucks & Oxon Regional Group), a Friend of SAVE Britain's Heritage and have recently completed a PD Diploma in conservation at West Dean College, with a view to achieving CARE accreditation. I hope to give you regular updates on my trials and tribulations as well as some insight into projects I am involved with and things I believe in.

Be patient with me - I'm no writer and I'm normally up to my eyeballs at work........

All views expressed here are my own.

Hurst Peirce + Malcolm, Celtic House, 33 John's Mews, Holborn, London WC1N 2QL

07854 624692 - richardsalmon9@gmail.com


Saturday, 12 March 2011

Our Georgian Adventure - Part 3

Welcome back to the Dunham Estate. This time the Gatehouse, built c1800 and located at the entrance to the estate some 400 yards away from the Lodge and listed by curtilage alone. As you can see this is a very small hotchpotch of a cottage loosely in the "Gothick" style with brick and flint walls and a pantiled roof. Almost unbelievably this cottage was still occupied by an old tenant (a bit of a hermit, but a very nice man - he had grown up on the Estate, where his mother had been in service at the Lodge).

This project was undertaken with a different local contractor, who whilst espousing conservation experience while tendering, showed very little of such during the works. A short leash was definitely required here! I'd like to think that by the end of the project, we had taught him a few things.

As before, I was acting as lead consultant and worked closely with the local Conservation Officer to achieve an acceptable result within a reasonably tight budget.

In order to make the cottage a little more habitable, it was decided to knock the two tiny bedrooms into one less small one and remove the badly damaged rear chimney breast/stack and latterly added concrete-floored pantry to create a reasonably sized kitchen/diner.

The estate gardener is due to take up residence shortly.

The Gatehouse as we found it. Roof and windows leaking badly and some foundation movement.
Two of the three chimneys close up. In a very sad state due to weathering and internal sulphate damage (and some very poor previous repairs).
The chimney breastwork corbelling from triangular to square within the loft space. Some cracking had us worried about stability, so reluctantly we had to introduce some steel strutting to improve the situation.
Some quite severe cracking in the more modern (c20) rear extension. After a year of monitoring and some soils analysis, movement was found to be ongoing, partly due to tree root action, but mainly because of very shallow foundations and seasonal moisture changes. To avoid the upheaval of underpinning, Uretek ground grouting was utilised beneath the existing foundations.
The existing brick floor as found. Whilst in part saturated and crumbling after years under  non-breathable vinyl flooring, we were determined to save this integral feature of the original building. We were additionally hindered by the Client's maintenance team removing one whole room's worth before we even got on site!
Imagine our surprise when we found this leaded window behind a tin sheet, which we believe may have been salvaged from an old chapel somewhere. This has always been a blank window so all a little bizarre. On the advice of a specialist conservator it was decided not to try and remove the window for repair so we have left it in-situ behind a new tin sheet with a photographic record to be left in the finished cottage.
We were also slightly surprised to find this intact cast iron grate behind the existing plaster. We knew there was a double stack so were expecting to find a fireplace, but not this!
Some of the windows were worse than others. Repairs were done in the workshop where possible, but two of the windows had to be fully replaced, like-for-like.
We also found this dilapidated brick shed in the garden. The walls were in reasonably good nick so the Client allowed us to bring this back into service too.
After lots of digging we found the original brick culvert under the estate access road. This was strengthened with a polypipe liner and the ditches re-dug as part of the estate-wide HLS funded drainage works.
The timber roof structure was found to be in surprisingly good condition with only minor repairs required to rafter ends and a couple of the dragon beams. Along the rear wall of the extension it was agreed to introduce a proper eaves overhang, as the previous eaves detail was very poor and had allowed water to penetrate into the top of the wall.
The reconstructed chimney stacks. The loss of the rear stack meant that we had just enough sound original bricks to complete the works. We used an NHL2 lime mortar here just to give a bit of extra durability (lime putty mortar used elsewhere). The precedent for the pots was taken from the remains of one broken gault terracotta piece found in the ditch. Internally the stacks were lined with EML and lime parging.
The early shenanigans with the brick floors meant that we ended up having to lift all. We therefore took the opportunity to install "insulated" limecrete floors throughout, achieved via the use of LECA (lightweight expanded clay aggregate) both as a subbase and as the large aggregate within the limecrete itself. No, the membrane is not a dpm, it's a breathable terram geotextile which helps to bind the LECA subbase.
The removal of the rear chimney breast left this purlin unsupported. We utilised steel angles to extend the span onto the (as yet unbuilt) new bathroom wall. the purlins were then encased in matchboarding to suit the existing detail. A new timber beam was installed beneath the existing beam here also, due to the loss of the pantry wall. (Yes, that is cellotex you can see. Didn't stay there long!)
Plastering underway. Two-coat lime plaster - scratch coat with hair, finish coat without. Note the matchboarding to the sloping ceiling to match the existing.
Brick floor relaid onto limecrete slab with sand bedding and jointing. Floor then "sealed" with a breathable polish that I was given a recipe for (beeswax and turpentine). We just about managed to salvage enough bricks from other parts of the estate to complete this.
Nearly done. Walls limewashed, old fireplace ready to be opened out. Existing doors retained and repaired, even though only about 1.6m high. When it came to heating we had a good headscratch, but at the end of the day the only sensible solution was this woodburner with back-boiler to feed the four radiators - one per room. Low capital cost and ready fuel supply on site. We made sure we chose one with a good slow-burn time so that reasonable ambient temperature could be maintained for long periods.
Et voila! The cottage finished. Ground levels slightly lowered and gravel strips installed to perimeter to help with drainage. (This photo is pre-snagging. Not happy with some of the flint panel pointing - now sorted!) Note the use of glazed (black) pantiles on three sides with red pantiles on the rear slope and catslide - all original, reused.
Having insulated roof an floor, we successfully argued with Building Control that the breathable solid walls did not need to be improved. We also commissioned some de-mountable secondary glazing for use in the winter months.
And finally, the shed brought back to life. Needed some brick stitching and new roof timbers, but otherwise quite simple. Another rarity saved.