Monday 11 November 2013

The Proper Use of Septic Tanks

Choosing/building a suitable septic tank

There are several key properties that your septic tank requires to be legally compliant and satisfy health and safety regulations.
  • Any factory-made septic tanks should meet the British Standard EN 12566-1.
  • If you have constructed your septic tank out of brickwork or concrete, ensure that it is roofed with heavy concrete slabs. Bricks used in the walls of the tank must be an engineering brick model that is at least 220 mm thick. Mortar used must be a 1:3 cement-sand ratio. In-situ concrete should be at least 150 mm thick.
  • The septic tank must have ventilation and this should be installed such that there is no leakage of the contents and the ventilation is kept from buildings.
  • The capacity below the level of the inlet of the septic tank should be 2,700 liters for up to 4 users then an additional for 180 liters for each user above that.
  • Ideally, there should be two chambers within the tank that operate in series and prevent immediate disturbance upon the entry of new waste through the inlet.
  • If the septic tank has a width of 1.2 metres or less then the inlet must be a dip pipe.
  • Steeply laid drains should limit velocity of incoming waste by laying the last 12 metres at a gradient of 1/50 or flatter to prevent turbulence.

Required marking of your septic tank

  • Nearby habitation must have a notice regarding the septic tank affixed to a wall.
  • The notice must state that the septic tank is in use for foul drainage discharges, the type of secondary treatment used, the maintenance required and that the owner is legally responsible the system does not cause nuisance, pollution or a health hazard.

Choosing where to place your septic tank

  • Ensure that your septic tank is at least 7 metres from any habitable sections of buildings.
  • If possible, place the septic tank downslope from any habitation.
  • Place the septic tank in a position such that it is within range of a hose such that the tank can be cleaned and emptied but does not endanger any occupants of nearby buildings.
  • The septic tank should be no more than 30 metres from any vehicle access point (to allow access for a tanker to take and remove the waste.
  • Ensure that the invert level of the tank is a maximum of 3 metres below the level of vehicle access.

Maintenance of your septic tank

  • The septic tank must be emptied at least once every 12 months by a licensed contractor.
  • An inspection must be carried out monthly of the outlet chamber or the distribution box to observe the effluent is free-flowing and clear.
  • The septic tank must be used in conjunction with a secondary treatment such as a drainage field, drainage mound or a constructed wetland & this will have its own maintenance procedure.

Tuesday 13 August 2013

How You Can Use Your Access Control System to Save Money

No, I'm not talking about the savings you make through reduced thefts of your property; but a clever way of integrating your access control system with your heating system.

The key is in being able to extract data from the access control system’s usage. Many systems used in large office, commercial or public buildings will store their usage data within a linked database. The idea is to extract this data and create graphs to show the activity within each room against the time and day of the week. You can then get an idea of which rooms are unoccupied at what times of the week. Then, you simply calibrate the heating such that when rooms are unused, they’re not heated.

The approach will not only significantly reduce your heating costs but is also a great way to improve sustainability. What’s more, it’ll look particularly impressive as it’s such an out-of-the-box solution in an area that can be quite difficult to improve & devise initiatives for.


A way to take this even further is to use a Building Energy Management System (BEMS). This approach is particularly useful for large buildings & organisations where the number of thermostats that need to be changed each day makes all those cost savings disappear into maintenance wages.

BEMS were designed to be more of a self-contained system that monitors temperature and other indicators throughout a building and respond accordingly. However, with clever use of databases and a little computer know-how you can automatically feed the BEMS the data from your access control system. The next step is to program the BEMS to apply heat loss algorithms to calculate the minimum amount of heat required for a building, based on which rooms are used when. The BEMS will also need to factor in routines; if an occupied or unoccupied room doesn't fit a developing pattern then the anomaly should be ignored.

Tuesday 18 June 2013

Part P: Making your Electrical Installation Safe

Part P is one of a series of documents approved by the Secretary of State (of the UK Government). Each document in the series is ordered by lettering; therefore Part P is the sixteenth approved document. The purpose of the documents is to explain to builders how to meet the Building Regulations 2010 for England. Although it not necessary to follow everything in Part P or any other approved document, you still have to comply with the Building Regulations, and the approved documents offer perhaps the best way of doing that.

Part P focuses on electrical safety; designing and installing electrical installations such that anyone who interacts with them is safe from injury.

Injury Risk Sources:
  • Electric shock. 
  • Fire hazards. 
  • Mechanical damage. 
  • Thermal damage. 

Electrical Inspections of Installation Work

One key part of the Building Regulations about electrical safety is that for an installation to be deemed safe, it has to be inspected by a ‘competent’ person. If you’re getting an electrician to do the job for you, then hopefully he is Part P certified (all of BPM Maintenance’s electricians are), because then he will be deemed a competent person and self-certify any work he carries out.

If whoever carried out the electrical installation isn't a competent person, then you’ll have to get certificate from a registered third party or a building control body, otherwise your DIY job will be breaking the Building Regulations 2010 legislation. That means if you do a DIY installation, then it turns out it isn't safe and someone gets injured, you’re going to have a bad time (not to mention your newly electrocuted friend).

Third Party Inspection

A registered third party could be an electrician who inspects your work when you’re done. If you’re going with this route, then you will need to arrange for this certification to happen within 5 days of work completion.

Building Control Body Inspection

If you want certification from a building control body, then you will need to arrange this before you start. A building control body will be part of your local authority. This body will ask you for your qualifications and competence with regards to electrical installations and then arrange for inspections to be carried out to ensure the installation is safe.

It’ll depend on your local building control body, but applications for electrical inspections can take weeks or longer to process with charges of £200+ or more.



Thursday 6 June 2013

Protecting Historic Buildings

The City of Bath in the United Kingdom is filled with historic buildings; the Government's Department of Culture and Media has over 2376 entries including over 5000 properties. Whilst these properties are lovely to live in, the downside is that residents are greatly restricted with regards to home alterations. What’s more, listed building owners have a responsibility to conserve the special characteristics of these buildings from degeneration and threats such as contaminants and moisture/dampness.

Protecting a Listed/Historic Building

The difficulty with this type of work is that you must balance alteration restrictions with the necessary changes to adequately protect the building from a different, more natural & unwanted 'alteration'.

Your local planning authority has a conservation officer who will know how best to handle this kind of balance, so it is definitely worth contacting them prior to carrying out work.

Protecting your Building from Radon Gas Seepage

Many listed buildings in Bath have a basement; the danger from this is that there is a large surface area in contact with the soil; i.e. the walls of the basement provide radon gas entry points from the soil as well as the floor. The primary gas entry points are cracks in concrete, floor-to-wall joints (where the walls of the basement and the floor meet), porous building materials and mortar joints (where two walls meet).

The key to dealing with gas seepage in a historic/listed building is by installing edge located sumps or sub-floor vents. Internal sumps or ducts will likely require the floor to be taken up, which should always be avoided in a listed building. If this is the only option and the floor of your building is flagged, careful recording of the position and layout of each stone should be carried out prior to the installation of the sump or duct.

Radon Sumps

A radon sump consists of an exhaust pipe from under the floor of your home for radon gas to escape through. It is the most effective way of reducing indoor radon levels and can be active or passive.
  • Active radon sumps are powered by an electric fan to propel gas out of the exhaust pipe.
  • Passive are not powered and are less effective, but they are sufficient for low radon levels.
One sump will be enough to protect the average home.

Sub-floor vents

An airbrick is perforated brick, with a grid of holes allowing air to flow through it. This can be an alternative to a radon sump when your building has a suspended floor; airbricks can be used to to allow air to flow beneath the floor.

Thursday 9 May 2013

Community Heating Systems

What is a Community Heating System?

A community heating system is where a single heat source supplies heat to a number of different properties. Examples include a system that heats a block of flats or a large scale heating system that supplies multiple buildings. Such systems work best in densely built areas with large numbers of dwellings in close proximity to one another; to ensure the system is efficient.

Systems across the world show a large range of different heating sources. Many use a typical boiler set up although new builds and refurbishments are often using renewable energy sources such as biogas or woodchip. Electric heating is particularly common with community heating systems due to their niche of heating densely built areas; a gas explosion could be devastating. Some community heating systems make use of solar and geothermal energy.

Here in the UK, some cities have adopted major community heating systems that heat whole districts.  In Nottingham for example, a community heating system heats 4,600 homes and a wide range of businesses.

How is the heat distributed?

Smaller community heating systems are similar to large scale central heating systems; making use of pumps, valves and insulated pipes.

The larger schemes use what are known as heat mains. Heat mains are series of pipes that are buried in the ground similar to other mains services and have stellar insulation to reduce energy loss and ensure optimum efficiency. A key feature of heat mains is that they can pump at different speeds, to adapt to what is required and keep costs at a minimum.

What differences will consumers see?

Consumers will still have radiators, thermostats, time switches/programmers and TRVs. The main difference is that instead of a boiler they have a Hydraulic Interface Unit which connects their home to the heat mains. This unit contains control valves and metering.

Thursday 2 May 2013

How to Choose a Stove with a Built-In Boiler

If you're looking for a stove with a built-in boiler, otherwise known as a cooker with an integral boiler, then there are some key specifications you need to know before you choose which one to buy. All appliances that are gas-fired are potentially dangerous and if mistakes are made possible results include explosions, gas poisoning or hefty legal bills.

It should come as no surprise then that there are Government regulations associated with the specifications of these appliances that must be followed.

The appliance must have two independently controlled burners

  • Both the cooker and the boiler parts of the device must have separate burners.
  • A gas burner is simply a device that burns the gas fed into the appliance, and uses the resulting flame to heat products, such as the water in the boiler, and food in the cooker.

The boiler must have a Seasonal Efficiency (SEDBUK) value at 75% or higher

  • SEDBUK was developed in a Government programme to accurately display boiler energy performance and allow comparisons between manufacturers of boilers.
  • SEDBUCK % scores are split into various bands.
  • You'll need to make sure that the boiler you're installing is upper band E (74%-78%) or higher to meet legal requirements for a stove with a built-in boiler.

Pipework should be insulated according to the regulations for gas-fired central heating system pipes

  • The primary circulation pipes for circulation of hot water & heating must be insulated whenever they pass outside of a heated living space or through voids (such as within walls) with are ventilated from unheated areas.
  • This insulation should extend as far as possible along their length, only excepting areas where structural or joist penetration renders this impossible ( a joist is a horizontal support member running between walls and beams).
  • If a secondary circulation system will be used, all pipes kept hot within this system must be insulated.
  • If the new appliance is replacing an old one, all newly exposed pipes must be insulated according to the above mentioned procedure.

The minimum provisions for gas-fired central heating must satisfy the regulations regarding integral central heating boilers

  • Further details will be covered in a separate blog post.

Boiler interlock, zoning, time control, temperature control, hot water circuits must meet minimum provisions

  • Further details can be found in this blog post about what these provisions are.
  • However, with this type of boiler/stove setup there is an alternative solution: you can use a boiler management system that includes zoning, timing and temperature provisions that meet the above provisions.
  • If you replace an existing boiler with the new appliance you will need to make sure the rest of your setup meets the regulations. However, if your current set-up is below standards and you're just upgrading a component such as a thermostat, then you will not need to upgrade the rest (although leaving your system below standard is inadvisable).

Monday 8 April 2013

Minimum Requirements for a Solid Fuel Central Heating System

When replacing an existing central heating system or installing a new one

System circulation of a solid fuel central heating system

  • Do you have a boiler interlock?
    • What is a boiler interlock?
      • A boiler interlock is where the heating system controls are arranged such that the boiler only activates when there is demand for heat. Heating controls include thermostats, programmers and time switches. The way an interlock is usually installed depends on the type of boiler used in the central heating system.
      • If you have a combi boiler then implementing a boiler interlock is as simple as fitting a room thermostat.
      • Central heating systems with regular boilers require special wiring interconnection of the motorised valve, the cylinder thermostat and the room thermostat or an advanced control such as a boiler energy manager. Some people claim that a thermostatic radiator valve will do the job - they're wrong.
    • If you do, then you will need fully pumped circulation in your new central heating system.
      • This means that your central heating system has a pump that moves all of the boilers heat to every part of the system (in comparison to systems that rely wholly or partly on gravity).

  • All instructions listed by the manufacturer of the heat leak radiators used in your new or replacement central heating system must be followed.
    • What is a heat leak radiator?
      • This is a radiator that has been installed in a position such that it will still receive water from the boiler by gravity, even if you're using a fully pumped circulation system. I write even, but you would actually only have this type of radiator in a central heating system that is at least partly pumped.
      • The reason for this is so that heat does not build up and cause a fire. The heat leak radiator is usually installed in the bathroom (often as a heated towel rack).

  • As this post is concerning solid fuel boilers; you must ensure that it is not fitted to a sealed heating system with expansion vessels unless explicitly stated that this is permissible by the manufacturer of the boiler or if you are using a thermal storage interface.
    • What is a thermal storage interface?
      • This usually involves a system where hot water from the boiler does not physically reach the radiators. Instead, a high insulated tank acts as an intermediate between the two.
        • Water pumped from the boiler heats the tank.
        • Water circulates between the radiators and the tank and is heated by the hot water within the tank (the water previously heated by the boiler).

Monday 18 March 2013

Installing Central Heating? Here's What You Need By Law

Installing a central heating system can be quite the complex task. It certainly isn't a matter of just buying a boiler, some radiators and connecting it all up with pipework. Here's a list of what else you need for your central heating to be both safe and legal:


  1. A Boiler Interlock:

  2. Any central heating system that uses a boiler to heat the water will need one of these. All the controls will have to be wired in too. Whats it for? Well, when no one currently wants heating or hot water, this will ensure the boiler and pump are switched off and not wasting your money. It also makes you greener (in a good way).
  3. Space Heating Zones:

  4. Unless your home is single-storey, open-plan and 70%+ of the floor is living area, then you're going to need to divide your house into space heating zones. Each zone you decide upon will need separate temperature controls. If your total usable floor is over 150m squared then your zones will also have to have separate timing controls.
  5. Water Heating Zones:

  6. Unless you're lucky enough to have a combination boiler, then it doesn't matter what type of house you have; you're going to need a special 'water heating zone'  in addition to your space heating zones.
  7. Time control of Space & Water Heating

  8. What you will need for adequate time control of your heating are either:
    • A full programmer with a separate timing to each circuit.
    • Two or more separate timers for each circuit.
    • A programmable room thermostat to the heating circuit with a separate timer for the hot water circuit.
  9. Temperature Control of Space Heating:

  10. To temperature control for your space heating zones, you can use:
    • A room thermostat in each of your zones.
    • A room thermostat in the main zone, then radiator controls like thermostatic radiator valves on all radiators in each other zone.
    • Or you can have both for some extra control over your heating.
  11. Temperature Control of Domestic Hot Water:

  12. For domestic buildings, your central heating system will need a cylinder thermostat and a zone valve or a three-port valve to control the temperature of the stored hot water.
    If your building has a floor area greater than 150 m squared then the best option might be to have multiple hot water circuits. You can do this by installing a multiple heating zone programmer, a single multi-channel programmer or separate timers for each circuit.
    If you are going to be using a non-electric hot water controller, you wont need this.

Thursday 7 February 2013

Introduction to Government Building Regulations

Government building regulations exist to safeguard anyone who comes within the vicinity of any type of building. They are designed to cover the technical details of building work to ensure that such activity does not endanger anyone.


What counts as building work?
  •  Building extensions or erections. 
  • Installation or extension of any fitting or service within a building. 
  • Any project that may change the compliance of the building or any services or fittings within the structure with fire or access regulations. 
  • Insertion of insulation to the walls of a building. 
  • Strengthening or stabilizing of the foundations of a building. 

What counts as a service or fitting in a building?
  • Toilets 
  • Showers 
  • Sinks & washbasins 
  • Hot water cylinders & boilers 
  • Drainage work 
  • Windows 
  • Any appliance that consumes fuel 

These regulations are necessary for work such as a loft conversion:
  • To ensure the structural strength of the floor 
  • To safeguard the stability of the roof and walls 
  • To ensure there remains a safe pathway to exit in the case of fire 
  • That there is sufficient sound insulation between the loft conversion and the rooms below 
  • To check whether the loft conversion is subject to the Part Wall Act 1996 and thus if neighbours must be given notice or not. 

The Party Wall Act?
  • A party wall is a wall that stands along the boundary of land and is used by 2 owners. 
  • If the loft conversion or any other building work involves a party wall then you must give the adjoining owners notice in writing about your plans. 
  • This must be served at least two months before the planned starting date and is valid for one year. 
  • The neighbour must give consent to your notice for the work to begin. 


BPM Maintenance is a building company based in the city of Bath that handles all building work in Bath, Bristol, Somerset and Wiltshire. Whether you need a loft conversion, a new shower fitted, a roof replaced or any other work that falls under these regulations, we are the company that can meet your needs.

Tuesday 15 January 2013

National Grid Prosecuted Over Gas Leak


The National Grid pleaded guilty on the 25th of September this year to breaching Section 3(1) of the Health and Safety at Work etc Act 1974 and was fined £17,500 in addition to £8,192 in costs after gas leaked into a Halesowen home.


The leak occurred back on the 20th of August, 2010 when a team of engineers replaced the gas supply to a property in Bromsgrove Road.

They chose to change the supply connection from a low pressure main on the opposite side of the road to a medium pressure main on the same side as the property.

Unfortunately, when carrying this task out, they drilled through a plastic main concealed within the iron main that they attached the new connection to. Gas leaked out of this secondary plastic main into a house 150 metres from the property the engineers worked on.

Thankfully the leak was noticed on the same day by a member of the public passing the property.

A second team of engineers was then deployed, identifying the high levels of gas within the house. The polluted house was then made safe in the early hours of the following morning.

The blame for the incident was placed upon the national Grid who had not updated records with the existence of the concealed plastic main. The company had know about the plastic main for four years, yet had not detailed this.

That the situation was speedily identified and resolved whilst the home-owners were out proved to be very lucky. Francine Cheney, a HSE (health and safety executive) inspector said that over half a tonne of gas had escaped from the incision made by the engineers. Such high levels could have killed quickly had the homeowners been inside. Additionally, as gas is extremely flammable, any form of ignition could have caused an explosion.

BPM Maintenance are a Bath based company with Gas Safe registered engineers that you can rely on toe perform jobs such as the one mentioned in this article efficiently and safely. They also offer gas safety certificates to Bath, Bristol and the surrounding area which landlords must obtain every year.

Monday 7 January 2013

Diamond Concrete Roof Tiles


The diamond concrete tile was invented in the 1840s by a man named Adolph Kroher in a small village in the region of Southern Bavaria, Germany. The style was introduced to the UK in 1895.

The tiles are designed in a diamond shaped pattern and this proved to never become a popular style, making it uncommon in its time and very rare to still exist on roofs today.

In fact one of the only known complete concrete tiled roofs in Britain is that of the former Minehead School. The roof is over 114 years old and has managed to endure little to no damage until the 2010/11 winter when some of the tiles were damaged. Unfortunately chances of finding replacements are remote and it is likely that facsimiles will be constructed to retain the building's appearance.

Today concrete is used quite commonly for flat roofs and flat roof tiles. Mission/barrel tiles are also constructed from concrete; this type is composed of alternating columns of semi-cylindrical tiles, with each adjacent tile on the roof protruding in opposite directions.

Concrete roofing is generally expected to last for about 50 years, making the Maiden School in Minehead quite remarkable. In comparison, other roofing materials such as asphalt are about one third of the cost but significantly less durable.

BPM Maintenance has skilled Bath roofers that are efficient, affordable and accredited with Trading Standards among other organisations.

One of the reasons that concrete roof tiles are so durable is because they can withstand high wind speeds that tear off other roof tiles. They are also resistant to damage from algae and moss although professional roofers can remove this to maintain a buildings appearance.