But what if I hit the mortar?

[WillyWarbux]

I'm about to put up a set of 5 heavy solid oak shelves. They weight about 7kg each with things like books to be sitting on them. I've decided to mount to the sides of the brick + plaster alcove they're going in rather than the back, which is a dot and dab wall.

I'll be using using 6mm x 50mm Fischer UX plugs, which on my tests, fix really well into brick. The shelves will be sitting on/screwed into 1 inch thick, 1 inch tall, home made wooden side brackets which run the same depth as the shelves (260mm). 2 screws in each bracket into wall.

I'll be wanting them equally spaced vertically up the wall and I was wondering what my tactics should be if I hit mortar?

• Is mortar useless to attach to? Can I can get away with it?

• Increase the diameter of the wall plug?

• Increase the diameter of the hole and insert some wooden pieces?

• Drill another hole a couple cm's left or right of the mortar and hope I'm not on a horizontal part of the mortar? (Add a 3rd hole/screw)

• Move shelf by 1.5cm vertically and make peace with the irregularly spaced shelves?

I have 10 holes to drill, so chances are I'll hit some of the crumbly stuff at some point. The house is 1930s so it's pretty old mortar too.

All comments and advice welcomed! Cheers,

 

[johnny2007]

Firstly i would use 8mm plugs.
Then, i have nothing against UX, but my favourite are the duopower.
If you hit mortar on one plug, hoover the hole, squeeze some gripfill in it and push the plug so it sets in the gripfill.
You'll need to wait for the gripfill to set before you can use a screw in it.
Mind you, this will be weaker than other plugs, so no over tightening.
If you get more than one mortar hole, buy some resin and you'll be ok.

 

[foxhole]

Fixing method is poor, needs fixing centrally as well as ends to prevent sag. You could use simple concealed fixing method instead of batons.

 

[WillyWarbux]

Fixing method is poor, needs fixing centrally as well as ends to prevent sag. You could use simple concealed fixing method instead of batons.

Fixing method IS poor, you're quite right. It would be absolutely sufficient if shelves were only 1m wide. But they're 1.4m. I did buy brackets, but was put off by the dot n dab wall. Would you go this route?

 

[foxhole]

Fixing method IS poor, you're quite right. It would be absolutely sufficient if shelves were only 1m wide. But they're 1.4m. I did buy brackets, but was put off by the dot n dab wall. Would you go this route?

I would mount them on screw heads left protruding from wall about 20mm, shelf having been notched to accept the screw heads which leaves no visible fixings .

 

[sircerebus666]

I would also go with hidden fixings (I think it looks better)

Even at 1m wide it's still a good idea to support the shelf in the middle to prevent sag

Why are you put off by dot and dab? You can still screw into the brick to get a solid fixing

 

[WillyWarbux]

Just thought I'd make a reply on this post as my shelves have been up now for just under a year.

Fixing method deemed poor seems fine so far. No visible sag. I used this tool to give me a little more confidence in my levels of sag: https://www.woodbin.com/calcs/sagulator/

I have 10 pieces of wood in my 5 shelves. 2 per shelf. Prior to putting them up I tested each plank to see how much each one buckled (25kg of weight in middle and measured with a ruler). I then paired the strongest with strongest and so on and placed the strongest pairing at the bottom, weakest at top, predicting that that the bottom shelves are likely to be taking most weight.

I've screwed shelves to brackets to also hopefully prevent future sag.

I hit mortar only twice out of 20 fixing holes. Managed to hit brick by moving a couple cms along on both of those mortar holes.

 

[cdbe]

They might sag if you put some books or stuff on them.

 

[WillyWarbux]

Heh, I didn't explicitly say, but yes, I've had some books n junk on them during the year.

 

[Stivino]

It looks great.