Advice with Damp Issue & Soil

[Shazeroo]

Hi. We have lived in our semi-detached Victorian house for 4 years, but over the past months we have had an issue with what appears to be rising damp in the ground floor bay. We lifted a floorboard and everything is completely dry. We have repaired a hairline crack on the window ledge and have just dug up an outside flower bed which was directly next to the exterior wall, below the damp area in the Bay - but the floor level is several feet above the flower bed. My question is what is the best option for the hole - we removed a large bush that had very deep, thick roots and now need to fill the hole in - should we replace the original soil or would it be better to fill it with gravel? I've attached photos of the damp inside and the hole and would be extremely grateful for any advice for the hole and what to do with the damp in the bay (which doesn't feel wet, just very stained). Thank you.

 

[ree]

OP,
Given your brick bonding pattern solid walls are suggested.
Solid walls allow for penetrating damp.
The bay has a brick plinth which has (what I think is) a sloping sand & cement fillet on the top - this fillet is possibly holding water thats then penetrating through the wall to appear on the inside of the bay as damp.
The fillet could possibly be an earlier attempt to deal with damp?

Best practice would be to carefully remove the skirtings & the rad - & then hack off all plaster back to brick, then render with a 3:1 mix of sand & NH lime - dont use any cement or gypsum plaster - skim finish with Limelite or similar.
This is not a cure for damp but it will give you 20yrs or so free from damp damage.

Examine the joist tails sitting in brick pockets in the bay, & all along that front elevation - look for rotting timber. You probably need more air bricks including a 10" x 6" a/b in the centre panel of the bay.

Fill the hole with soil to just below path level.
Have you located a DPC?
The RH side of your house is probably getting the most down hill ground water.

 

[Shazeroo]

Thank you so much for all that advice and information. The previous owners lived here for 28 years and said that the bush was growing at that time, so if the 'filet' was added at a later stage to when the house was built, it would have been at least 35 years or longer ago. Also, exuse my ignorance, but which exact bit is the 'filet' - do you mean where the wall comes out from the painted area below the render or is it the concrete looking part deep in the hole? We have lived here for 4 years and never had an issue until this year. I will pass on everything you've said to my husband and he can take the floorboard(s) up again to check the joint tails - we did take one up and everything was complete dry, but I'm not sure he check right at the end. There are 2 air bricks on each side of the bay window, but nothing in the middle panel, so your advice to add one in the middle will hopefully help. Can I just clarify that it's OK to fill the hole with the existing soil, but to keep it below the level of the terrace? Thank you again for taking time to help us with this, it is genuinely appreciated.

 

[^woody^]

Fill that gap in with whatever you like.

The internal tide line of the damp appears too high compared to the external ground levels to be rising from the ground.

Presumably there is a DPC, just below the floor boards level, and it may be more likely that the issue is water penetrating down from the cill or the plinth fillet and settling on the DPC.

Do the cills have a drip detail (groove) on the underside?

Are all the joints on the cill and frames intact?

Is the paint proper repelant masonry paint and the render intact?

 

[Shazeroo]

That makes sense as the floor level is a lot higher than where the flower bed is. The windows were replaced 3 years ago and we have started checking them to see whether they could be causing the problem. My husband started working on the exterior cill yesterday where there was a few 2 - 3 mm cracks and he found out that the drip groove on the underside was bunged up with silicone sealant (presumably when they fitted the new windows they didn't clean it off). He has removed the sealant from the drip groove and he renewed the caulking between the window and the concrete cill (keeping the groove clear). We weren't sure whether this could have been causing the damp, so it's very useful to hear that it could well be the case. The paint is Santex Exterior masonry paint and there are a few areas where this is flaking - mostly lower than the floor level but they will be scraped and repainted. Could it have taken a few years for the problem to show if it is the windows causing the issue? Thank you again for all your help. S

 

[^woody^]

Check for and repair all the defects on the exterior, then dry the internal wall - fan heater and ventilation, or dehumidifier and no ventilation. It could take a few weeks.

Whilst this is going on, monitor the plaster for signs of increased damp after lots of rain fall.

If things are drying off, then all's well. However, previously damp plaster can become hygroscopic - attract moisture from the air. This can appear similar to damp but will often have associated white salts. If this occurs, the plaster will need to be replaced.

 

[Ivor Windybottom]

Leave the beds as empty holes. The next time it rains heavily, get your raincoat and brolly and have a look at what's happening out there.

Downpipes, gutters, drains, surface water.

Otherwise you're just guessing.

 

[Shazeroo]

Thank you - it would be useful to see where it drains away to.