Why do external render bids come in low in Qardho?

External render bids come in low in Qardho when the rate covers only labour, sand and cement, and the contractor leaves out scaffolding, curing water, surface preparation and rain protection. The price looks competitive because it counts the visible trowel work and nothing around it. The fix is to compare each bid against one scope list before you award.

What do low external render bids in Qardho leave out?

The biggest gaps are usually access, water and preparation, not the render mix itself. A rate built from a quick look at the wall can miss the scaffolding, the curing water and the hacked-back surface the work needs.

Watch for these omissions:

• Scaffolding, ladders, working platforms and the labour to move them around the elevations.
• Curing water: where it comes from, how it is stored on site and who keeps the wall damp.
• Surface preparation: brushing dust off blockwork, hacking smooth faces and filling deep joints before the first coat.
• Curing time in the programme, and protection from sun and wind while the render sets.
• Rain protection and making good around openings, sills and pipes.
• Waste, mixing losses and cleaning down splashes.

Ask each bidder to price these as separate lines. A bidder who cannot explain how water reaches the wall, or how the top of a two-storey elevation gets coated, has left the cost for you.

How does weather exposure damage an underbid render?

A render priced without curing and rain protection can fail in the first season, and the damage shows up after the retention period. In Qardho the Gu and Deyr rains are the test: water sitting against a wall with no drip detail finds every crack the render already has.

Bags of cement should be stored off the ground under cover, and the wall should not be coated in the heat of the day or just before rain. General practice is to keep fresh render damp for several days, and to confirm the curing duration against the project specification or the engineer. A price that excludes the water cart, the hessian or the tarpaulin is a price that excludes curing.

Porous blockwork and a wall that dries unevenly can leave shrinkage cracks that track water inward. Ask the contractor to describe the sequence from substrate to finish, and ask the municipal engineer's office what it holds on local exposure or drainage near the plot. Then check what the contract says if water turns out harder to get than the bid assumed.

How do you detect an unrealistic tender allowance in Qardho?

Compare the render rate against the scope, the programme and the site, not against the other bids. Two contractors can quote the same wall with completely different assumptions about access, water and time.

Run these checks:

• Measure the render area from the drawings and compare it with the bid quantity.
• Ask for the mixing ratio, coat thickness and curing period in writing.
• Walk a recent render job by the same team and look at the junctions, sills and the base of the wall.
• Ask for the manufacturer's or supplier's written mixing and curing instructions so the rate can be checked against them.
• Ask two suppliers for written quotes on the materials, and ask the laboratory for its rate if testing is required.

When the numbers do not add up, the bid is usually missing a line rather than offering a better method. Any deviation from the specification should be confirmed with the project engineer before work starts.

What to do next

Ask every bidder for a line-by-line breakdown of the external render, listing scaffold, water, preparation, curing and rain protection separately. Compare the measured area against the drawings and walk one completed render with the same team. Put the agreed scope, curing method and weather protection into the contract before the first mix.