How to construct a ring beam to hold your house for years

(Credit: Umar Nsubuga)

CONSTRUCTION

Beams are used in construction for a multitude of purposes. In our day-to-day construction of houses, beams are used to boost structural integrity of brick/block walls.

Aaron Kulindi, a quantity surveyor, says structural stability is one of the most important factors to consider in construction.

According to Kulindi for high-rise buildings, a lot of emphasis is put on the foundation, making sure it is firm so the upper structure is supported.

"That is why the bigger the building, the deeper and more complicated the foundation, and the reverse is true," he says.

Architect Abdu-Wahab Nyanzi says the most common beam is the ring beam, used to tie up the whole masonry works into a single operating unit.

"When it comes to building residential houses, the foundation is not as complicated as it is for high-rise buildings with more than four or five floors, since the weight to be supported is not the same," he weighs in.

However, the foundation can only support so much weight from the base. And as the walls of the building come up, there is a load exerted directly by the roof onto the walls and may turn out to be hazardous if not property contained by the walling units.

This necessitates the installation of a ring beam, which supports this weight from the roof structure, which mainly constitutes timber and iron sheets.

Muhammad Nsereko, also an architect, says the foundation and the walling sections of the building are first constructed, then the ring beam is introduced on top of the brick or block wall.

He says the most basic type of ring beam is made of reinforcement and concrete. The reinforcement is usually made of T12 and R wires.

According to Kulindi, when the maximum wall height has been reached, timber form work for the ring beam is nailed on top, creating an extension of approximately nine inches above the wall.

He says the reinforcement wires are then inserted into the form work and the concrete is poured in.  "This concrete is usually a mixture of cement, sand and aggregate. The concrete is left to set for a period of about two weeks, then the timber form work is removed".

He also says the ring beam runs along the wall and it is here that the wall plate sits. One of the advantages of houses constructed with a ring beam is that chances of the wall cracking due to the load from the roof structure are minimal.

Nyanzi says for houses without a ring beam, the points of openings where doors and windows are found become points of weakness, where cracking in the walls may originate.

Ring beams also reduce the tendency of sagging in the walls. Besides the tendency to enhance structural stability, the ring beam also adds beauty to the design of the house.

This is because in most cases, houses with ring beams have a more aesthetic appeal compared to those without.

Depending on the size of the building, the overall cost of the ring beam will vary but one should put into consideration estimates arising from these costs.

Classification

Nsereko says that classification of beams is mainly based on positioning in the building parts, for example walls, suspended slab, roof part among others.

Ground beam

He says this one binds the foundation wall together and is fixed on the ground.

Suspended beam

Nsereko says that this is found in between floors or in between walls.

Ring beam

This normally makes the end of the constructor of brick work just before roofing; this is commonly used on bungalow and storeyed houses with an upper part to take on piped roof instead of a flat roof.

Tie beam

This is the beam used by timber and it supports the roof fusels.

Common materials for beams

Reinforced concrete is the most used.

Steel is used between big structures where large spans are needed.

Timber is mainly in roof frames, but it is also used in simple storeyed slabs.