How to fill gaps in bricks?

[gemmaco]

Hi there,

Looking for some advice please to fill some gaps in and around our windows. 

Additionally, I'd like to fix up an area where it looks like old expandable foam has been used. I've scrapped back what I can, but wondering if I can use more foam on top of it before adding some outdoor sealant. Is that a good idea? 

Thanks so much for your advice! 

 

[JacobZ]

Hi @gemmaco,

It looks like the gaps are mainly because you have some fairly empty mortar joints between your bricks. Filling these joints up is referred to as "repointing", and it is fairly common and relatively easy to do.

With a few of the joints, it looks like you might need to remove a bit more mortar to have enough room to effectively repoint them. Generally, you need about 20mm of depth to effectively repoint brick joints, as there needs to be sufficient surface area for the new mortar to adhere to. In areas where you need to remove some mortar, you can use a Masterfinish Small Poly Wheel Raker, or an angle grinder with a diamond wheel.

Once the mortar joints are prepared, you would use a standard mortar and push it into the joints using a pointing trowel or brick jointer such as this Kango 10mm/13mm Brick Jointer, smoothing it out as you go.

Once the mortar joints are filled and dry, you can assess whether there is any additional sealing required. The window has a rubber seal which should sit over the bricks and prevent any water seeping through the seam, but if there are still small gaps that you are concerned with, a bead of Sika 600ml Black Sikaflex 11FC Purform applied beneath that rubber seal would certainly be worthwhile.

Let me know what you think and if you have any further questions, please don't hesitate to ask.

Jacob

[gemmaco]

Thanks Jacob! What would you suggest doing about the expandable foam in the second picture I posted?

[JacobZ]

Hi @gemmaco,

I'm not seeing a second picture with expandable foam. Can I trouble you to try uploading it again?

If you're having trouble, feel free to send it through to workshop@bunnings.com.au and I can upload it for you.

Jacob

[gemmaco]

Thanks. Hope it's come through this time. I've gotten as much of it out as I can, but wondering what next? 

 

[JacobZ]

Hi @gemmaco,

Yes, it has come through this time.

While expanding foam, used in this application, might be effective in terms of keeping out water and draughts, it is not easy to make it look nice. Personally, I'd be removing it and using the Sikaflex 11FC Purform that I've mentioned above, as when applied in a consistent bead, struck off and smoothed, it gives a much nicer finish.

Removing the expanding foam could be done with a combination of things, such as a paint scraper or a wire brush. If it is particularly difficult to remove, an angle grinder with a flap disc would be effective, but you'd need to be careful not to damage the window frame in the process.

Once it has been removed, I'd assess the mortar joints and repoint them if needed, then apply a bead of Sikaflex 11FC Purform. 

Have a look at How to repair window flashing and How to replace exterior window flashing and gaps between window, as these discussions are fairly similar and offer guidance on the process.

Let me know if you have further questions.

Jacob

[AlanM52]

Hi @gemmaco,

Follow @JacobZ's suggestions and I will add a couple of things that do.

You can also make your own mortar picker

Use the one that has the heavier gauge wire.

I transfer mortar to the joint using a small straight edge putty knife, pack it in then finish with the brick jointer.

For small jobs I mix up in a kitty litter tray.

Cheers