If you’re still catching up on The Block lingo, like House 3’s Taz, there’s one word this week causing a lot of drama.

And we mean ‘redo all the tiles in your bathroom’ level of drama.

That word is ‘Mastik’, the tile glue sending this year’s Blockheads into a tizzy. Here’s the biggest reason why.
“They had to redo what?!” (Nine)

What is Mastik?

Mastik D2 is a premixed tile glue and a popular choice among contestants this year.

The builders from Nine in Six however, don’t like it when contestants use Mastik on The Block simply because the tile glue takes seven days to fully dry before you can start grouting.
The culprit. (Nine)
We’re on The Block, we don’t have seven extra days here!

Without drying properly, the trapped moisture can dislodge tiles and cause major problems down the track.

As House 4’s Sonny explained: “For a quick turnaround like this, it doesn’t work.”

So, Mastik isn’t the bad guy here, it was how the Blockheads were using it.

With only 40 hours until Room Reveal, Houses 3 and 4 faced a tiling nightmare.

In this instance, both houses used Mastik, the wrong type of glue on their tiles. Site Manager Aiden delivered the gut-wrenching news that every freshly laid tile had to come back off their walls.
Aiden is the bearer of bad news. (Nine)
But more on that in a sec.

How did House 5 get away with using Mastik?

During a fast turnaround like The Block, teams can get away with using Mastik depending on the type of tile they used.

A porous tile, such as ceramic, has tiny holes like a sponge that can absorb and release the moisture. While a non-porous tile such as porcelain is tightly sealed.
Porous tile vs non-porous tile. (Nine)
Luckily, House 5’s Robby and Mat used the right tiles, meaning their glue dried a lot quicker than the other houses.

But that doesn’t mean there wasn’t a problem to fix.

“One of our sections in our bathroom, our tilers had put on the grout before the glue had set,” Mat explained.

The easiest way out of it, was to carefully scrape out the grout in that section to get air to the glue. What’s an extra two hours work?

How about a whole day’s work?

Houses 3 and 4 however used Mastik on porcelain tiles which meant every freshly laid tile on their walls had to come off, on a Friday night.

Put simply, the product wouldn’t have dried properly and their bathroom wouldn’t be up to code.

“Has that happened?! Is that real?” Mat reacted.

The Mastik drama continues…

Not thrilled. (Nine)
“All the tilers and myself just sat in a bathroom fully tiled ready for grout… just dead silence,” Taz recalled.

“You put in all the hard work, you see all your beautiful work up on the walls and they say you’ve got to tear it down. It was tough.”
Gutted. (Nine)
It was one step forward was 10 steps back for Sonny and Alicia who also used Mastik on their porcelain tiles.

“It was an absolute disaster,” said a shattered Alicia.

After they spent all night ripping off their tiles, they notice the waterproofing membrane was also ripping.
Dan tried to warn Sonny and Alicia after spotting the glue in their bathroom. (Nine)
You live and you learn! (Nine)
“We’re now waterproofing Friday. Everyone’s emotional, my tilers are emotional, I’m emotional,” Sonny said.

A pep talk and plan of action later, they were in much better spirits but it was sure a tough lesson learned.