Hollow soft bricks on outside leaf

[garyo]

I had a dreadful time putting a replacement door on my sisters house today. It's a 1990s build.

The bricks appear to be normal soft facing stocks but seemed to be hollow when drilled in to. The first time I thought I'd just hit a bad/hollow frog but every brick was was the same.

I made a good enough job of it in the end by using 120mm Thunderbolts and putting six down each side of the door, but it didn't fill me with job satisfaction.

Any ideas what I was drilling in to? Have any kind of hollow bricks been used in recent new builds (ones that aren't just frogged bricks). Maybe they were running out of mortar and laid them upside down...

[edited to remove mobile phone brevity]

 

[foxhole]

Have you read you own post?

 

[leew2]

They maybe the type of brick with 3 holes through them (a "perforated" brick), the holes vary in size but can be about 50mm in dia. It could be that you drilled into these holes.