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Thursday, 31 January 2013

Repointing Lime

Re-pointing irons for lime repointing jobs

In the UK we are used now to see repointing being done using a pointing trowel or a brick jointer. However doing a proper job with lime mortar requires a different set of tools. 

This is because joints should be cleared by a depth of more than their width, as a very thin layer of mortar might not adhere (BRE guidance is for all but the narrowest of joints is that the depth should be twice as great as the width of the joint).

The skill requirement for raking out should not be underestimated; it is all too easy to remove the edges of stone and bricks, especially if the joint has been filled with cement mortar. Traditional lime mortars are relatively soft and should be raked out by hand with a sharp instrument. A simple spiked instrument should suffice, although where the mortar is sound it may be necessary to use a sharp chisel or flat bladed quirk. However, if the lime mortar is sound, the question that must be asked is whether it is necessary to remove it or not. 

After the masonry has been correctly prepared for re-pointing the matured mortar should be thoroughly knocked-up to the consistency of glazing putty, The the mortar should be pressed firmly into the pre-dampened joint void until it is filled out to the face and feels solid. Mortar spreading out into a thin layer across the facework must be avoided, as this can lead to future water penetration. The jointing tool required to deliver and press in the mortar must be one that fits the relevant joint sizes. Small trowels may be adequate for large joints in rubble stone walls and some types of brickwork, but for fine masonry purpose made jointers or pointing irons should be used.

When the mortar is applied it is extremely workable, but be aware that it rapidly becomes much firmer as moisture is drawn out of it by the masonry. It must then be gone over to compact and consolidate it and bring it to the required profile and finish. Different finishes can then be created using a brush or jointing tools depending on what effect you are trying to achieve / match.

Tuesday, 29 January 2013

Missing tape causes concern

Tape in buildings? Isn't that for covering over mistakes and bodging joints?

Tape has been historically used as a cover for poor workmanship, but it is now becoming a necessary tool for many modern building materials and designs. When you look at how buildings (inc refurbishments) manage to pass the regulations regarding airtightness and heat loss, they are becoming increasily reliant on tape to join together membranes and insulation boards.

On a recent visit to a leading Builders Merchants I was after some breather membrane and its associated tape. The customer service personnel were quite surprised that I asked for tape - "What for?" I explained and they said that they don't keep that in stock due to no demand!! So it looks as though the specifications being used by architects etc is not being put into practice on the ground.

Taping is really important for board insulation and membranes to work properly, otherwise you get thermal bridging as air passes around the boards or between the membranes. This means that your house / extension will not be performing as specified and you will be losing heat / potentially allowing water ingress etc. Taping is therefore essential and you should check at regular intervals to make sure that it is being used as specified / required.

However, just to add an extra bit of spice into the equation. How many people open up their walls / floors / roofs to check to see if the tape is still intact and holding? I would guess absolutely none. So how do you know that the tape used is still doing its job, especially in areas where it is subjected to extreme temperatures and pressures (notably in roof constructions)? Apart from re-testing airtightness at home, the best way of ensuring that the building continues to perform as designed is to use a good quality tape to start with.

Good quality tape is not widely available. So most builders will use whatever they can get. At Eco Home Centre we would recommend using tapes from those companies who are building Passiv Haus type homes. So ProClima, IsoChemie etc. We have some ProClima Tescon #1 tape in stock if needed. However the important thing is to be aware that taping is now an integral part of achieving modern building regulations and that a little investmest in reliable tape will go a heck of a long way to ensuring on-going comfort in your home.

Monday, 28 January 2013

Green Deal Launch

This is the headline diagram that the Gov wants people to see. On the face of it, it looks great. Same bills, but a more efficient home, all with no up-front capital expense.

Personally I think that this can the case for some homes; making our homes more efficient can save money and if you have no capital to spare then this is a way of getting a loan against the house not you as a person.

There are a wide number of Green Deal Approved measures (pdf file from DECC) - new boilers, insulation, draught proofing etc. The choices are generated by a computer programme called rdSAP (Reduced Data Standard Assessment Procedure). This programme is not the best calculator, but it is the UK industry standard. It also lacks a lot of the relationships between interventions that might be very important for your home. So some interventions might have unintended consequences. The worse of these is the relationship with moisture in the home. Older solid walled houses are really at risk by the use of some insulation products (unfortunately these are the most efficient and cheapest types of insulation). RdSAP will tell the assessors and the Green Deal providers that large savings are available if you use these insulations. What it doesn't tell them is that it it likely to cause damp to migrate inside, or that external wall finishes might face damage. So be careful if you have a solid walled home.

The other issue that is not being mentioned, is that there is a built in 7.5% interest rate with the Green Deal. So you might well be better off just using savings to do the work, or by re-mortgaging as this will be much lower cost than the high interest rates demanded by Green Deal.

Many measures will be very expensive and will not make too many savings. For example; new windows, underfloor heating,  heat recovery systems etc. So it will be a high cost for little return, so the Golden Rule (savings are more than then cost of the measures over a set time scale) will require that you put in a lot of your own money to make sure that you are not breaking this rule. So again it is more complicated than it initially appears.

What having a Green Deal loan secured against a house will do with re-selling that house is yet to be tested, but it might be a concern to people.

Overall I think that the Green Deal is an opportunity for some to take advantage of energy savings, but people need to go into the dreaded detail to ensure that it is the right choice.

Tuesday, 22 January 2013

Pipe lagging

Many of us are running around lagging external pipe work at the moment, what with this cold snap. Always a good idea as it is an unpleasant surprise to find water gushing everywhere when the thaw comes, especially if you are on a meter.

Lagging, though, is also really important inside the home as well.

Hot water pipes run all across the home and they are losing heat all the time when you really want all that hot water in your sink / bath / shower. This applies to all months of the year. Lagging therefore helps to get hotter water where you need it.

Not only this is useful about lagging. As the water in the pipes cool down quickly, when we want more hot water in the sink soon after someone else has used it, we generally faced with now tepid water coming through. So we have to let all that tepid water out and wait for the newly heated water to come through again. This is especially so with combi boilers. So all the energy that has gone into the hot water is just lost to the atmosphere. This is a real waste. So lagging the hot water pipes helps to slow down heat loss and so you should find that you can now use that hot water in the system rather than having to wait for the freshly heated water to come through.

This is a saving not only in expense and carbon but also in water. With water set to become a more precious resource (even though last year was almost the wettest on record, it also had the driest winter and spring with a hosepipe ban in lots of areas) it is important that we use it wisely.

If you are lagging your hot water pipes, you might also want to think about the cold ones in high humidity areas like bathrooms. Cold pipes attract condensation and this can lead to a series of issues depending on your particular circumstance. Carpets might get dripped on and start to get mouldy and rot, tiles might get slippery when wet etc. So bear this is mind if you do get the lagging bug!

Lagging is a relatively cheap process, but can be awkward to fit, so we would recommend lagging pipes that you can see and then trying to remember to get hidden pipework done when you are having improvements made. It is a simple, effective and cheap solution to help us do our bit, but it is so commonly overlooked.

Plumbers should really lag all new pipework, but in refurbishments it rarely happens, so mention it to your plumber next time you see him / her and see if we can spread the message about the importance of lagging pipes.

Wednesday, 16 January 2013

Home Surveys - are they worth it?


I am flabbergasted.

I have been to a newly purchased house in Cardiff where the new owner had been told that the house had some damp and that there was some repair work required to the guttering.

Thankfully, because of an article I wrote a few years ago in the South Wales Echo (about old terraces being similar in structure to castles), I got a call about if I could cast my eye over the property.

What I found was unbelieveable.

The front of the house was damp - due to a blocked gutter, poor silicone seals around the windows and some poor pointing. This had meant that the plaster inside had failed, the skirting is rotten and more importantly the floor joists had rotted (well the floor was very bouncy!)

The back of the house, though, was soaking. Guttering to blame? Well partially (they were blocked), but this was nothing compared to the blown, cracked and missing cement render all over the back of the house. This might explain the mouldy walls, the water staining, the failed plaster, .... The remedy, is of course, to scaffold the whole of the back, hack all the render off and re-render using a lime putty one, repaint using a breathable paint (limewash). Then the inside also needs to be taken back to the stone and brick and replastered, ...

The new owner was expecting to spend a bit of money getting the outside done and had plans for new kitchens, rewiring, new heating system etc.

So I was the bearer of bad news. But how can people be so misled? Terrible, just goes to show that most surveyors are not trained in older properties and hence have no idea about how buildings work.

It reminded me of another building I saw last year where they had paid over £750 for a full survey. It noted some damp and that a damp specialist be brought in and a damp proof course installed. It failed to note that the area affected already had a damp proof course. It also failed to note that the west facing window above the affected area had a great big gap all around it where the silicone seal had failed. So the customer was getting poor advice that would have cost a lot of money, whereas the solution was actually very simple and cheap.

Bit of a worry really, especially when buying a house is probably the biggest investment of our lives and the 'professional' advice that we get can be so poor. If you want our input then have a look at our pre-inspection reports.

Tuesday, 15 January 2013

earthborn paint changes


Just a quick heads up for anyone interested in earthborn paint.

Three big pieces of news:

1. The claypaint and associated eggshell palate will be increasing from the standard 36 colours to 60 colours. Some colours will be disappearing from the colour card, but will still be available if required. This will give you greater choice (which can be seen as a good or a bad thing I suppose!)

2. Earthborn have developed a new 'Midsheen Emulsion' to extend their EcoPro range of paints. This is a durable, hard wearing, washable finish that is ideal for high commercial traffic areas (or indeed in hallways / stairwells that tend to take a battering!) This has been used and tested with Lush Cosmetics who use it in all their new stores and refits. This will be a UK made product in a standard, but good, colour range that provides a great alternative to the claypaint.

3. The worse is last. There will be a price increase effective on 1st April, so if you want to get your claypaints, emulsions and eggshells at the old prices please order before the 27th March to ensure that deliveries make it to you before the 1st April.

Thankfully Eco Home Centre has permanent discounts on earthborn prices and we shall continue to offer these discounts, however since the starting prices will go up, we will have to increase our prices a bit to cover our increased costs.

Happy planning your new look at home!

Friday, 11 January 2013

Stone in Cardiff and surrounding homes

In Cardiff and South Wales we have a number of different stones that have been used over time for building houses. These stones came from a variety of sources:

1. Red Radyr Stone.
2. Bath Stone
3. Pennant Stone
4. 'Dock' stone

1. Radyr Stone is a breccia sandstone from Radyr (oddly enough)  which is a sedimentary rock. It contains irregular fragments of white, brown and grey rock. It formed in a hot dry climate where occasional torrential rain led to flash floods. These carried rock debris along wadis, which was then dumped as alluvial fans at their mouths. Over time, the fragments were cemented together with sand and calcium carbonate.

2. Bath Stone is a limestone, another sedimentary rock. It contains a lot of shell fragments  cemented together with calcium carbonate. The quarries for this stone are around the Cotswolds in SW England.

3. Pennant Stone is a grey sandstone. Most of the quarries were around the Valleys of South Wales.

4. This is a made up term by me to illustrate where the stone came from. Basically as the ports grew the amount of ballast coming back with the coal and iron ships grew as well. The stone used for ballast came from a variety of sources - SW England, France, Ireland etc. This meant that it was a mix of stone types. This helps to explain why you occasionally hit a lump of granite (very hard igneous rock) when drilling into a stone walled terrace house.

Understanding these stones help us to repair them and maintain them properly. The sandstones and bath stone are permeable, but their porosity varies. Limestone in the Bath Stone and Radyr Stone means that these are softer and more porous than the Pennant Stone, however all should be repaired using permeable / breathable materials. We would recommend using Lithomex for stone repairs as this comes with a great reputation. This is available through Ty Mawr Lime in Brecon.

Also remember that when rendering over stone lime based renders and plasters should be used, NOT cement. If painting stone then use a breathable paint not a standard masonry paint. We would recommend earthborn Silicate paint.


Wednesday, 9 January 2013

Draught proof letter box solutions

Many of us have draughty houses and one source of these draughts is our letter box. Having been leafleting around Cardiff recently it is amazing what bad shape our letter boxes are in. Some are inoperable, others are missing or severely broken, some have bristles in a variety of conditions. So is there a way of making them work and still be permanently draught proof? Well I think that there are two main options.

Firstly, Ecoflap have a retro-fit system that still allows post through easily whilst maintaining a draught proof finish when not in use. So if you have an existing draughty letter box then this might be just the ticket. Available in white, brown and black from Eco Home Centre.
Ecoflap have a retrofit draught proof system
Secondly, there is the option of not having a letter box in your door. This is the system that we recently employed at home. With new doors going on we didn't want to spoil them by putting a hole in them, so we plumped for an external letter box. This has worked well to date.

External letter box saves making a letter box in the door

Wednesday, 2 January 2013

Bathroom extractor choices

When we fit extractors in bathrooms we either nip down to our local DIY store or we rely on our builders to get an extractor. This effectively means that we get the cheapest and most common extractors on the market. These are generally controlled by the light and if we are lucky we get a timed extractor. However, there are a number of other choices that might just provide you with a better solution for your home.

The main overlooked choice is an Humidity Controlled extractor. These are slightly more expensive (but not by much) than standard extractors, but they do have the great advantage of managing humidity in a room where moisture can be a problem. They are also adjustable so that you can set the level that is best for your home.

The other options are PIR controlled extractors. These basically sense whether there is someone in the room and switch the extractor on appropriately.

Both of these can also have timers involved so that they continue to run after the bathroom has been vacated. Also it is worth noting the wattage, volume extracted and the noise levels of your extractors.

For those who have fairly airtight homes you might be interested in investing in a Heat Exchange Extractor. These are significantly more expensive, but can be worth while thinking about if undertaking a major refurbishment project.

The other major issue with extractors is allowing them to work properly. Avoid placing the extract so that it faces the prevailing winds. A west facing louvre will be blown closed and also rattle a lot, it may also form a weak spot in the wall and allow wind driven rainwater into the wall. Ideally we would recommend venting the extract to the north and / or east and preferably through the eaves of the roof.