Dear Heather

My husband and I have seen a house we like, and ideally would like to add an additional bedroom. That means the cesspit has to be moved is that difficult to do?

Moving a pit

Dear moving a pit

It’s not the huge deal people sometimes imagine it to be, however it will require some heavy equipment, a contractor and a plumber. To move the pit you do need planning permission, but this can be done under a minor work development application which takes about a week.

Bear in mind that pits must be ten feet from any boundary, ten feet from any building (even a garage), 20 feet from any water tank or pool, and 40 feet from any shoreline.

Also some low-lying properties can be too close to the water table, in these instances a fibreglass pit can be installed, the contents of which do not seep into the ground, but are pumped out every few years when full. Kitchen and bathroom waste should be separated by a solid wall (if not separate pits).

The minimum size of a pit is six feet by four feet by six feet deep, which is 144 cubic feet, about 900 imperial gallons. This serves up to a four-bedroom dwelling.

If any further bedrooms are added, the pit size must be increased by 24 cubic feet, which is about a 150-gallon additional capacity, for each bedroom. So if you think that you may want to add on later, it would be prudent to work out where the addition will be going and increase the size of the pit accordingly. To collapse a pit, it just requires it being pumped out, and filled in with a backhoe.

Contract-built pits can be built on hard rock (divided with a wall for the 2 different types of waste, with just a slab over the top which must sit on a 12 inch to 18 inch shelf. If the property sits on soil or sand, a proper footing and walls need to be built to support the slab, or one of the precast concrete pits are ideal for these types of conditions.

The lifetime of a pit can be extended by using a product such as RidX, which will encourage the good bacteria that help break down the solid matter.

A structural surveyor would look for sinking in the area of the pit top and frog holes around the sides. This indicates that the pit either needs to be replaced (new pit relocated) as the surrounding rock may be saturated and build-up on the interior could prevent proper drainage. Otherwise, a concrete slab can be precast on the ground nearby and then when the old one is removed, moved into place quite quickly minimising the unpleasant smell factor.

The premade pits are made by Bierman’s, and I met Mike Bierman who supplied me with the following information.

Premade pits weigh 6,600lbs and are made of structural-grade concrete reinforced with rebar. They are made at Bierman’s one at a time. On the top, they have a paving stone for access and a pipe for ventilation.

Bierman’s have a mould which opens outwards and puts 5/8inch rebar at the top which forms handles and acts as part of the reinforcement. This makes it easy to move with a crane truck.

The production machine produces ready-mixed concrete and is poured into the mould. Once dry, the pit is popped free using vibration, compressed air and a crane. Although the premade pits are structurally sound and very solid, no pit (of any type) should be installed anywhere, where a vehicle could potentially drive over them. If that is going to be the case, an engineer should be called in to advise on proper reinforcement, vehicles include water trucks and fire trucks.

Each premade pit holds 1,000 gallons and normally a seven-foot cube needs to be dug into the ground to accommodate the mould. The pits have weep holes which are blocked on construction but can be opened afterwards.

If two pits are placed side by side (1 for the kitchen and 1 for the bathrooms), the weep holes are only opened on the sides that do not abut the adjoining pit. Once on site, the pit cannot be manoeuvred easily by a regular truck. Therefore it should be positioned on an accessible side of the house. Bierman’s was the first company to produce these type of pits, and hundreds have been sold island-wide. They should last for many, many years, probably outliving the average purchaser. Once in place, they can be covered with soil, and just become part of the garden.

• Heather Chilvers is among Coldwell Banker Bermuda Realty’s Leading Sales Agents. She has been working in Real Estate for nearly 30 years. Follow “Ask Heather Chilvers Real Estate” on Face Book, and “heatherrealtorbermuda” on Instagram. If you have a question for Heather, please contact her at hchilvers@brcl.bm or 332 1793. All questions will be treated confidentially