Over 100 steel-timber structures risk demolition for noncompliance, says govt
The banned method limits the use of concrete and steel, by replacing some of the load-bearing elements with timber. PHOTO/COURTESY
What you need to know:
- NBRB investigations manager Eng Anthony Rucukye said they are convinced that the banned method is generally unsafe and not viable from a structural point of view.
Government is set to destroy about 138 structures established using the banned Steel-Timber Concrete (STC) Composite Building Method in districts of Kampala, Mukono, Mpigi and Wakiso, authorities have said.
According to works and transport minister Gen Katumba Wamala, the crackdown follows his September 23, 2022 Legal Notice No11 of 2022, which prohibited STC for being comparatively risky in building operations.
“Between July 1, 2022-June 30, 2023, the National Building Review Board (NBRB) monitored 2,954 ongoing building operations in Kampala, Mukono, Mpigi and Wakiso where 138 (4.7 percent) of these were found to be using this method,” Gen Katumba said while receiving the NBRB technical report on STC composite at his office in Kampala on Thursday.
The minister said the number of buildings to be destroyed will depend on the further critical analysis that will be conducted by the NBRB officials through a unique committee.
NBRB investigations manager Eng Anthony Rucukye said they are convinced that the banned method is generally unsafe and not viable from a structural point of view.
“We are going to further review the ongoing 138 sites and if we find the one that can be remolded and reshaped, we shall save them but those that can’t be remolded will completely be destroyed and rebuilt,” he elaborated.
Gen Katumba advised the developers of already existing STC structures to engage qualified professional engineers to carry out structural integrity assessments.
“The building committees should refrain from approving building plans without a design report, drawings showing connection details, sizing of structural elements, specifications for materials, and geotechnical investigation reports,” he added.
STC Composites
STC ‘Composite’ is the method of construction that incorporates steel, timber, and concrete in its primary structural elements. It combines structural steel framing with a floor slab system of timber joists supported by steel beams.
The timber joists are typically 100x100mm and spaced at 600mm intervals. An expanded metal lathe is nailed to the bottom of the timber framework, filled with pricking up mortar, and another layer is nailed to the top, creating a void between the concrete topping and the ceiling soffit.
The concrete topping, lightly reinforced with BRC mesh, is then cast on top of the mild steel expanded metal
