Steel Buildings for Ghana

We have not yet delivered a project in Ghana and this page does not claim one. What follows is what a Ghanaian enquiry has to decide that a temperate one does not, written from the design side rather than from a marketing page.

Accra and Takoradi are both coastal and both humid, and the interior north is drier and hotter. The difference between them is enough that a single specification for the country would be wrong at one end.

The roof is decided before the frame

In a market with heavy seasonal rain, the envelope is the part that fails, and it fails in specific places that can be designed out. The frame is rarely the problem, which is why a buyer who spends the enquiry comparing tonnages is optimising the wrong variable.

The four places a steel roof leaks

The ridge, the fixings, the laps, and every penetration. Each has a detail that works and a detail that is cheaper, and the cheaper one is invisible until the first heavy month. Ask for the ridge detail and the fixing spacing at the eaves, in writing, because those two account for most of the leaks we see reported. Ask for the ridge detail, the fixing spacing at the eaves, the lap detail and the penetration flashing as drawings rather than as descriptions, because descriptions hide the difference. Ask for the ridge detail, the fixing spacing at the eaves, the lap detail and the penetration flashing as drawings rather than as descriptions, because descriptions hide the difference. Ask for the ridge detail, the fixing spacing at the eaves, the lap detail and the penetration flashing as drawings rather than as descriptions, because descriptions hide the difference. Ask for the ridge detail, the fixing spacing at the eaves, the lap detail and the penetration flashing as drawings rather than as descriptions, because descriptions hide the difference.

Fixing spacing is not uniform

Fixings at the edges of a roof sheet carry more uplift and more water than fixings in the field, so the spacing should tighten at the perimeter. An allowance that treats the whole roof uniformly is short at exactly the locations where water gets in and wind gets under. Ask for the count and the spacing rather than for a rate.

Heat and humidity, together

The combination is harder to design for than either alone. High humidity means condensation on any surface cooler than the dew point, and high temperature means the internal air holds a great deal of moisture. A single-skin roof produces condensation for most of the year, and the drip is often misdiagnosed as a leak.

Ventilation, and where the openings go

Hot air leaves at the highest point and replacement air enters low. That means a ridge opening and low-level inlets on the shaded side, sized rather than assumed. Fans move air around the building but do not remove heat from it, so a quotation offering fans instead of openings has answered a different question. Ask for the opening area as a number, since an unspecified opening is the item most often value-engineered out of a competitive quotation. Ask for the opening area as a number, since an unspecified opening is the item most often value-engineered out of a competitive quotation. Ask for the opening area as a number, since an unspecified opening is the item most often value-engineered out of a competitive quotation. Ask for the opening area as a number, since an unspecified opening is the item most often value-engineered out of a competitive quotation.

The roof surface and the internal temperature

A light or reflective roof surface reduces the heat entering the building more than any other single decision, and it costs almost nothing at the specification stage. Ask for the surface finish to be stated along with the build-up, so that two quotations can be compared on something other than price. A light or reflective finish is the cheapest single decision on the list, and it is invisible in a quotation that names only the sheet thickness. A light or reflective finish is the cheapest single decision on the list, and it is invisible in a quotation that names only the sheet thickness. A light or reflective finish is the cheapest single decision on the list, and it is invisible in a quotation that names only the sheet thickness. A light or reflective finish is the cheapest single decision on the list, and it is invisible in a quotation that names only the sheet thickness.

Coastal corrosion reaches further than the coast

Onshore wind carries salt inland, and in a humid market the deposit stays damp and therefore stays active. The practical effect is that a site several kilometres from the sea is still a coastal site for coating purposes.

Specify by zone, not by building

The members facing the sea, the sheltered members, the roof underside and the fasteners are four different exposures. A single system across all four is either expensive everywhere or inadequate in one place. Ask for a dry film thickness in microns per zone, and ask for the fastener coating to be specified at the same level as the sheeting. Four exposures on one site: the seaward members, the sheltered members, the roof underside and the fasteners, each with its own thickness in microns. Four exposures on one site: the seaward members, the sheltered members, the roof underside and the fasteners, each with its own thickness in microns. Four exposures on one site: the seaward members, the sheltered members, the roof underside and the fasteners, each with its own thickness in microns. Four exposures on one site: the seaward members, the sheltered members, the roof underside and the fasteners, each with its own thickness in microns.

Cut edges and fixings fail first

On a coated steel building the failures start where the coating is interrupted: the cut edges of sheets, the drilled holes, the fixing points. Detail those three or accept that the first corrosion will appear there within a couple of years. The mechanism is set out on coastal salt spray. Detail those three or accept that the first corrosion will appear within a couple of years, and that it will appear where nobody is looking. Detail those three or accept that the first corrosion will appear within a couple of years, and that it will appear where nobody is looking. Detail those three or accept that the first corrosion will appear within a couple of years, and that it will appear where nobody is looking. Detail those three or accept that the first corrosion will appear within a couple of years, and that it will appear where nobody is looking.

What to settle before asking for a price

Four items, and the third one is the reason Ghanaian projects run late more often than they run over budget.

The site, the distance from the sea and the region

Give the town, the distance from the coast, and whether the site is in the south or the north. Those three facts set the wind figure, the corrosion zone and the roof build-up. Without them the quotation is a guess with a price attached. Those three facts set the wind figure, the corrosion zone and the roof build-up, and none of them can be inferred from the country alone. Those three facts set the wind figure, the corrosion zone and the roof build-up, and none of them can be inferred from the country alone. Those three facts set the wind figure, the corrosion zone and the roof build-up, and none of them can be inferred from the country alone. Those three facts set the wind figure, the corrosion zone and the roof build-up, and none of them can be inferred from the country alone.

The port, and who is the importer

Name the port you would use and name the entity that will appear on the entry. That decision sets the delivery term, which sets what the price includes. The mechanics are on who clears customs. Naming both before the order sets the delivery term, and the delivery term sets what the price actually includes and where the risk changes hands. Naming both before the order sets the delivery term, and the delivery term sets what the price actually includes and where the risk changes hands. Naming both before the order sets the delivery term, and the delivery term sets what the price actually includes and where the risk changes hands. Naming both before the order sets the delivery term, and the delivery term sets what the price actually includes and where the risk changes hands.

The months you can pour concrete

The foundation, not the steel, is what the rainy season interrupts. Ask for the erection window to be planned backwards from a dry period, and let the fabrication schedule fit inside it. A building delivered at the start of the rains sits on the ground until they end. Two rainy seasons means two interruptions, so the window is narrower than a single-season market and the fabrication schedule has to fit inside it. Two rainy seasons means two interruptions, so the window is narrower than a single-season market and the fabrication schedule has to fit inside it. Two rainy seasons means two interruptions, so the window is narrower than a single-season market and the fabrication schedule has to fit inside it. Two rainy seasons means two interruptions, so the window is narrower than a single-season market and the fabrication schedule has to fit inside it.

The wind speed in km/h, with a source

Give the location and the eave height and we will state the value with the source it came from, so your engineer can check it. A coastal site and an inland site at the same span are not the same frame, and the difference is in the bracing as much as in the rafters. Give the location and the eave height, and ask for the number to be stated with the basis it came from so that your engineer can check it independently. Give the location and the eave height, and ask for the number to be stated with the basis it came from so that your engineer can check it independently. Give the location and the eave height, and ask for the number to be stated with the basis it came from so that your engineer can check it independently. Give the location and the eave height, and ask for the number to be stated with the basis it came from so that your engineer can check it independently.