Weeds and brickwork

Walker34

Hi,
I have an old house and there is a plinth about 25` up from ground level. Every couple years weeds (with long stems with purple flowers) start growing from the plinth. They cause water to get in and over the following winter frosts loosen the masonry. I need to prevent this from happening. I want to re-cement the brick with a mix that is water resistant and hopefully will discourage weeds from taking root. I am thinking of capping them with a 45 degree slope to help runoff. Should I cover them with Mastic or tanking material as well.......the gloves are off this time.! Working from a 25 foot ladder is a pain so I need a permanent fix to this. anyone got any ideas.?

ART6

Walker34 wrote: »

Hi,
I have an old house and there is a plinth about 25` up from ground level. Every couple years weeds (with long stems with purple flowers) start growing from the plinth. They cause water to get in and over the following winter frosts loosen the masonry. I need to prevent this from happening. I want to re-cement the brick with a mix that is water resistant and hopefully will discourage weeds from taking root. I am thinking of capping them with a 45 degree slope to help runoff. Should I cover them with Mastic or tanking material as well.......the gloves are off this time.! Working from a 25 foot ladder is a pain so I need a permanent fix to this. anyone got any ideas.?

I'd first clean off the old masonry and make sure it has no dirt residues, then paint it with watered down PVA adhesive (from any DIY store or builder's providers). Then do as you say and form a new surface, sloping to assist run-off. I'd use a strong mortar mix of 2 1/2 parts building sand to 1 of cement. When it's set, paint over it with more watered-down PVA to seal it and make it waterproof. I find that more effective than the proprietary waterproofing solutions.

The instructions for use on PVA containers usually suggest the amount of water needed to create a waterproofing solution.

slowburner

It could be worthwhile too to give the area a spray with simazine before you carry out the work to make sure that any remnants of the weeds (probably Buddleia) don't regenerate.

Walker34

Thanks for the info folks