How to move garden beds away from a wall?

Question

Hi,

We have recently moved to a house where  garden beds have been set up directly against the wall of the house around the entrance door and in the backyard.

We understand that this is a termite risk in the current set up and would like to find a solution.

What are our options to protect the walls?

I’ll note that the house is built with brick foundation straight on dirt, and the garden beds do not block the vents to the subfloor but clearly some plant watering has gone through. The grass is fake.

Thanks for the help!

Nailbag · Answer

Hi @LauraLtrn

Personally, I wouldn't be too concerned about the current relatively small low lying garden layouts. Unless you're really saturating the gardens on a very regular basis, then I doubt what little if any moisture gets through the sub-floor brickwork is causing long term issues.

With the house on stumps and providing the sub-floor breather holes are clear and open and the garden beds are kept well below their level, then your cross flow ventilation should be working as it should. No other prevention should be required unless rising damp is or becomes an issue within the home. The front of the house looks like its directly on a concrete slab so, no issue with low lying garden beds are going to be an issue there either. Again as long as they are kept below vent holes

Low lying garden beds between a masonry glad home and pathways is pretty common practice and rarely the cause of any issues providing the above notes are in place. Placing a row of pavers between the house and garden isn't going to prevent water from going under them. The barrier would need to go down to the depth of the footings.

I would also doubt that the garden beds are any high-risk for termites. But if you're concerned, then getting the property sprayed for termite protection and continuing that yearly would suffice. Pest control experts can also advise if your area is subject to termites etc.

Bear in mind that depending on state the majority of building inspectors are unregulated and/or don't have a range of specific trade qualifications. Many are ex-carpenters who have switched professions. At tend to take the reports as a basic guide as in my experience, every inspector I have used over the past 20yrs in a regulated state has missed very obvious defects, some being serious. That said, if you have concerns in any area of the building report, then my advice is to get in services that specialise in them to inspect and recommend action.

At this stage, other than getting a pest service to spray for termites, I wouldn't be doing anything unless the rising damp is already an issue.

Nailbag

EricL · Answer

Hello @LauraLtrn

Subfloor humidity is commonly caused by a combination of factors, including moisture migrating through surrounding soil, inadequate subfloor ventilation, poor site drainage, leaking services, or garden beds positioned against external walls. While a narrow-paved area may help reduce the amount of surface water reaching the wall, it is unlikely to fully prevent moisture transfer through the adjacent soil.

The most effective long-term solution is generally to excavate the soil away from the affected wall, expose the external brickwork, and apply a suitable waterproofing membrane such as bitumen paint to the outside face of the wall. This helps prevent moisture from passing through the brickwork and entering the subfloor area. Applying a waterproof coating to the internal side of the wall is generally not recommended, as it can trap moisture within the brickwork itself, potentially leading to ongoing dampness and deterioration over time.

It would also be worthwhile to ensure that garden beds are kept below the level of any damp-proof course, that surface water drains away from the house, and that subfloor ventilation is adequate. Addressing these factors together will provide the best outcome in reducing subfloor humidity and protecting the long-term condition of the home.

If you need further assistance, please let us know.

Eric

LauraLtrn · Answer

Thank you both!

We are satisfied with the current look of the garden beds. Although esthetics are definitely important for us, we also believe they should not compromise the long term integrity of the house.

In the current situation, our building inspector raised an issue with subfloor humidity, we would like to avoid the water from the garden beds to be wicked in the walls and contribute to the subfloor dampness.

Would creating a 20cm paved area along the walls be sufficient to deal with the problem? Do we have to put anything under the pavers?