The Hidden Gaps Between Design and Waterproofing Installation - And How QS Helps Close Them

Where Things Go Wrong — And Why It Happens

In New Zealand construction, waterproofing is one of the few trades where small design gaps lead to big on-site problems.
Not because architects do a poor job—but because waterproofing is highly dependent on:

• substrate conditions

• sequencing with other trades

• membrane compatibility

• detailing that must match supplier requirements
  

Architects draw the intent. Installers deliver the reality.
The space in between? That’s where details get lost. And that’s where a QS becomes critical.

The Most Common Design–Installation Gaps

1. Missing Junction Details

Things like balcony upstands, internal–external transitions, or nib junctions often lack the precise detailing needed for a clean install.
Without clarity, installers are forced to “interpret” the drawing… which leads to rework, delays, and disputes.

2. System Specs That Don’t Match Site Conditions

Designs might specify a membrane suitable for ideal conditions—
but on-site the substrate moisture, fall, or levels tell a different story. QS insight identifies the mismatch early, not mid-install.

3. Incorrect or Missing Quantities

A drawing may show a simple shape, but the QS sees:

• vertical surfaces

• returns

• negative details

• additional layers

• priming allowances

• detailing not shown on plans
  
  

This is why QS quantity accuracy protects margin and reduces variations.

4. Sequencing Conflicts With Other Trades

Waterproofers often walk into sites not ready for them—
because the drawings don’t reflect site logistics.
We see this often in:

• podiums

• planters

• commercial roofs

• internal wet areas
  
  

A QS identifies these clashes early, aligning scope with site reality.

How QS Insight Closes These Gaps

✔ Turn drawings into real-world quantities

QS analysis interprets every plane, every turn, every upstand—
the way an installer actually applies it.

✔ Align system selection with supplier standards

We ensure specs, CAD details, and installation guides match the chosen system.

✔ Identify missing details before tendering

This is where the biggest money and time is saved.
One clarification early eliminates five variations later.

✔ Provide clarity to both builder and applicator

A QS report creates a single source of truth for:

• scope alignment

• inclusions/exclusions

• sequencing expectations

• detailing requirements
  
  

This is why builders trust QS-backed waterproofers more.

Why This Matters More Than Ever in NZ

The NZ waterproofing sector is tightening:

• higher expectations on compliance

• tighter margins

• more complex systems

• increased supplier involvement

• rising quality and documentation demands
  
  

A QS bridges the gap between design theory and installation reality, making your quotes stronger, your installs smoother, and your variations fewer.

Make Every Detail Count

At AQUOSYNC, we specialise in QS-driven waterproofing takeoffs that connect drawings, supplier systems, and real-world installation needs. If you want clearer scopes, fewer surprises, and stronger project outcomes -
we’re here to help.

👉 Talk to us about your upcoming project.