Cellar restoration project, Devon

Cellar restoration project

Prior to us becoming Earthouse Building Conservation Ltd, we were just plain old Earthouse. One of the first projects we undertook as Earthouse in 2002 was this fantastic cellar restoration. The customer rang us the other day to discuss another project at her property and when I went to visit I couldn’t resist asking for another look at the cellar! Unfortunately in 2002, I don’t think I had a phone that could take photos and I wasn’t keen on lugging a camera around building sites, so I don’t have any before photos to show you, but this is what the cellar looks like now.

Cellar restoration using lime render, Devon

The cellar restoration was part of a larger project at the house. Myself and the owners were unsure of the history of the house and the reason for the niches in the cellar – was it used to store food? Wine? Someone even suggested it looked like a morgue for infants. I am not sure about this theory! As you can see the owners now use it to store wine, a great use for a unique space. For more information about cellar restoration, there is an article in the Building Conservation Directory.

Lime plasterwork

The niches in the cellar have been carved out of an extinct riverbed, we could see the layers of silt when we started restoring the cellar. There were a number of structural repairs we had to carry out prior to the rendering, which we did using cob blocks, lime mortar and then coated with lime render. This was then lime washed. Limewash is a great product but it does need redoing relatively regularly to keep it looking fresh and to maintain its’ protective qualities. The cellar has not been lime washed since we did the original work, hence why it is looking a little tired. We will post an update once we have carried out the new lime washing.

If you have a project you would like to discuss further, please Contact Us.

A guide to Cob and Lime Maintenance

Cob and Lime Maintenance

We talk a lot about restoring cob and lime buildings on this site – probably because by the time Earthouse has received a phone call, there is already a problem! In this blog we are going to talk about maintaining your building so that you do not get to this point.

Unfortunately, if you can see the problem, it generally means there is something underlying. In the worst cases we have seen, this has been severe damage due to complete deterioration of the cob structure. The most common reason customers contact us is to say that there is a crack in their plaster, or a damp patch has appeared. When we hear this, we know that the issue will be that a cob or stone wall has been rendered using modern cementitious render. Modern cementitious renders have their place; on modern buildings with a damp course and effective air circulation systems. They were never meant to be used on cob or stone walls and consequently cause problems.

Water damage to decorative plaster

Water damage to decorative plaster

The damage is almost always caused by water ingress. Modern cementitious renders are waterproof; this means that if water somehow gets in it cannot escape, so it remains within the structure and moisture builds up over time. The frost and thaw process aggravates this deterioration, resulting in the cob degrading into a topsoil-like substance.

However, cob buildings if treated correctly can last for hundreds or even thousands of years; as long as you are prepared to spend money putting right what previous generations have got wrong, there is no reason your building cannot last for a similar timespan. In addition to this, conservation officers will no longer allow you to render cob in sand and cement, as this does not conserve the integrity of the building.

Cob and Lime Specialists

As a cob and lime specialist, if we can see cracking or damp on your walls, we will assume that there could be issues with the underlying cob. They may also say that they cannot diagnose the extent of any damage without being able to see beneath the plaster. As a guide, if you have excessive or large visible cracks to the render, you should expect a number of cob repairs.

Whilst it is straightforward to give a cost for lime rendering per square metre, it can be difficult to provide a quotation for remedial cob work. Generally Earthouse advises customers to allow a 15-20% contingency for cob repairs, although this may differ depending on the situation. There is no steadfast way to deduce the state of the cob without taking the render off; we have worked on properties where the render looks fine, but the cob is really badly affected underneath. Conversely we have taken off badly damaged render expecting the worst, only to find that minimal cob repairs were required.

Structural repair to cob wall

This shows an extreme example where the cob structure had been undermined at the base of the wall and was subsequently repaired by Earthouse

How to avoid cob deterioration

If you have a cob property there are things that you can do to maintain the integrity of your building.

Cob cottage with cementitious render removed

Cob cottage with cementitious render removed

  • Prior to buying a cob property, you might consider asking a cob and lime specialist to accompany you on a site visit. If the property has been rendered in anything other than lime it may be that you can negotiate on the price, as ideally you would re-render the house.
  • If you suspect a cob property has been plastered in cementitious materials, ask the surveyor to confirm the render material and the paint used.
  • If your house is cob, always consult a builder that has specialist knowledge of cob and lime render.
  • Remove aggressive creeping plants at the earliest opportunity as they can damage structures. Be aware that any plant or tree that touches the building can affect the render negatively, particularly if it is windy.
  • Damaged or blocked guttering is probably the most common cause of water ingress; check your gutters and ensure they are cleared regularly.
  • Thatched houses tend not to have guttering; ensure there is an alternative way to drain excess water away from the house, for example via a French drain soakaway.
  • If you have anything other than lime render on your walls we would suggest that you remove this internally and externally. If you have a cob property, this will then need to be re-rendered in lime based products. Stone or brick properties without a damp course will need to be treated with lime based mortars throughout.
  • If removing the render internally and externally throughout the house is not an affordable option, it may be that there are key areas that you could restore to prevent further damage.
  • Use the correct decoration on walls that have already been lime rendered. We recommend lime wash or you could choose one of the excellent silica based paints internally. Externally you also have the option of using a casein distemper or a clay based paint. Please see our blog Lime Wash vs Silica Paint for more detail.
  • If you decide to use lime wash, bear in mind that you will need to re-decorate within 3-5 years to maintain your aesthetics.

Finally if you are concerned about your property, please contact us. We are able to provide free advice about the best way to approach any remedial or preventative work.

Pinterest – amazing pics that we love!

Amazing inspiration on Pinterest!

We have recently discovered Pinterest – and we love it! There are so many inspirational ideas on there from all over the world. We have pinned some amazing images that are relevant to us.

What we like:

  • Cob: cob houses, cob ovens, cob huts
  • Lime: lime render, lime plaster, lime wash, different colour lime
  • Plasterwork: decorative plaster work, Venetian plastering
  • Tadelakt: we just love this stuff! Amazing images of Tadelakt rooms, bathrooms, pools – beautiful!
  • Lots of inspirational images!

If you see something on Pinterest that you think we could help you achieve in your property, please share it with us.

In the meantime, have a look at our pinboards here

Pin our photos!

If you like any of our photos, you can Pin them by hovering over the image and clicking on the red PinIt! button.

Just the formal bit: Pinterest is not formally associated with Earthouse as a brand and in no way sponsors anything we do!

We haven’t used any of the images from Pinterest on our webpage, but here are some of our examples showing creative cob, lime and plasterwork.

Photographs below belong to Rowan Pettitt.

Blue lime wash in Jodhpur   Blue limewash, Jodhpur

Brilliant blue limewash in Jodhpur, Rajasthan.

Cob and thatch huts Cob and thatch huts, Rajasthan

Cob living and working hits in Rajasthani desert. Amazing carpets are spun here!

Painting on lime render

Painting on lime plaster in Udaipur, Rajasthan.

Lime Rendering

Lime rendering and plastering specialists

Lime is an amazing product; it is breathable so buildings release any damp, it is natural, it is versatile and although it is a traditional material used for thousands of years, it can also look very modern.

Earthouse can offer a range of lime rendering from hydraulic setting to traditional lime putty render.

External finishes are designed to be highly textured, which not only creates a tactile effect, but also ensures that the exterior achieves maximum breathability due to the larger surface area.

Internally we can create highly polished lime plasters or beautiful textured lime render finishes. We will always discuss your desired effect and we are able to give advice to ensure the integrity of traditional properties is maintained.

Examples of three different effects can be seen in the pictures of our recent projects below.

External lime rendering

Lime rendering

The Walronds – Grade 1 listed building in Cullompton – rear aspect

The Walronds - lime render

Front aspect of The Walronds facing into the High Street

Church lime rendering

Contact us - restoration of window surround

Westwood Church – old lime render removed

Lime render and plastering

Westwood Church – new lime plaster applied

Lime render and plaster

Westwood Church – newly lime rendered, plastered and lime washed.