The Sahihi blog · 22 guides
Guides for buildings that have to last.
How to keep water out, keep tiles down and keep concrete sound, written for Tanzania's rain, heat and coast, with the figures taken from the manufacturers' own data sheets.
All guides
Waterproofing9 min read
Why hidden roof houses leak, and the fix that lasts
Hidden roof leaking? Find the leak point: parapet, gutter, outlets, slab or cracks. Causes, types of fix and stocked products, with data sheet figures.
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Waterproofing6 min read
Waterproofing an underground water tank
Underground water tank waterproofing: joints, pipes, drinking water coatings, consumption per m² and the wait before filling, from the data sheets.
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Waterproofing6 min read
How much waterproofing per square metre: a kg/m² guide
How much waterproofing per square metre: data sheet kg/m² for each stocked product, m² per pack, and a worked bathroom example with the wall upturn included.
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Waterproofing6 min read
Cementitious, liquid or acrylic membrane: which one
Cementitious, liquid or acrylic membrane? Compare the three families from data sheets: uses, exposure and consumption, for bathroom, roof, basement and tank.
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Tiling6 min read
How much tile adhesive per square metre
How much tile adhesive per square metre: printed rates for four adhesives, m² per 25 kg bag, a worked 30 m² room and why the trowel changes the figure.
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Tiling6 min read
Why floor tiles pop up, lift or sound hollow
Why tiles pop up, lift or sound hollow: a table of six causes, what to check on site, the fix, and how joints, coverage and curing time prevent it.
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Tiling6 min read
Epoxy grout or cement grout: which goes where
Epoxy grout vs cement grout compared from Mapei data sheets: joint width, working time, cleaning, where each belongs, and the +30°C limit in Dar es Salaam heat.
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Tiling6 min read
Tile adhesive or sand and cement: which to use
Tile adhesive vs cement: thick-bed sand and cement against thin-bed adhesive, why porcelain needs adhesive, and when a screed still comes first in Tanzania.
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Tiling7 min read
Keraflex Maxi S1, Adesilex P7, Kerabond T or Mapeset: which Mapei tile adhesive
Mapeset, Kerabond T, Adesilex P7 and Keraflex Maxi S1 compared by class, consumption, pack and limits, from the data sheets, to pick the right tile adhesive.
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Tiling8 min read
Mapei waiting times: when to tile, grout or walk on it
How long to wait before tiling, grouting or walking on Mapei products: membranes, adhesives, grouts, levelling and primers, with each printed condition.
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Flooring6 min read
Why epoxy floors blister and peel, and how to prevent it
Why epoxy floors bubble, blister and peel: moisture, humidity, dew point and poor preparation, with the limits data sheets print and how to prevent each.
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Flooring6 min read
How thick should an epoxy floor be: coating to screed
Epoxy floor thickness explained: eight resin floor types from 150 microns to over 6 mm, what thickness buys, and the material it takes per square metre.
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Flooring6 min read
Self-levelling compound: how many bags per square metre
Self levelling compound per m2: 1.6 to 1.7 kg per mm. Bags by area and thickness for Ultraplan Eco 20 and Contract, with water and primer quantities.
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Flooring6 min read
How soon can you tile or lay vinyl on levelling compound
Self levelling compound drying time: minimum waits before tiles, vinyl, carpet and wood from two Ultraplan data sheets, and what humid air changes.
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Flooring7 min read
Screed or self-levelling compound: which does a floor need
Screed or self-levelling compound? Compare thickness, waiting time before tiles, vinyl and wood, and how each is laid, using figures from Mapei data sheets.
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Tools and technique7 min read
Joint sealant sizing: width, depth and metres per pack
Joint sealant width to depth rules from three data sheets, the sum for sealant volume, and a table of metres per 600 ml and 4 litre pack, before wastage.
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Tools and technique6 min read
Trowel notch size by tile size: a metric chart
Trowel notch size for tile size in mm: Mapei notches, wet bed, back-buttering and how to check coverage by lifting a tile. No guesswork, data sheets only.
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Tools and technique6 min read
Mixing tile adhesive: paddle, speed and water
How to mix tile adhesive: water per 25 kg bag for Mapei adhesives, standing time, pot life, low-speed mixing, and what heat does to open time on site.
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Concrete repair6 min read
Rusting rebar and falling concrete: a repair guide
Spalling concrete repair, step by step: why rebar rusts and bursts the cover, how to clean and coat it, rebuild the section, and how much mortar to order.
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Concrete repair6 min read
How to grout a base plate with non-shrink grout
How to grout a base plate: prepare and soak the concrete, form and head, mixing water, one-side pour, curing, and a worked example of how many bags to buy.
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Building in Tanzania8 min read
Construction companies in Tanzania: CRB classes explained
How CRB classes work for construction companies in Tanzania: categories, class limits, storey caps, how to check a contractor and what to ask before signing.
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Building in Tanzania7 min read
Masika and vuli: a builder's rain calendar for Tanzania
When masika, vuli and msimu fall in each Tanzanian region, from TMA, and when to schedule roof waterproofing, concrete pours, terrace tiling and resin floors.
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