I live in a mid 19th century property where the main 30ft long living room has exposed and sealed 7" wide x 1" thick floorboards. There is a void of about 18" under this floor which looks down onto exposed dry earth. The floorboards are not tounge and grooved and there are smallish gaps between the boards ranging from about 1 to 3 mm. My problem is that this living room regularly has an earthy, musty smell which I believe must eminate from under the floor. This smell is generally only noticable when you first step into the house and lessens as your nose gets used to it. It is however particularly noticable on windy days when I pressume the increased air flow though the air bricks blows the smell up into the room. All the underfloor timbers where professionally spray treated about 2 years ago and some joists were replaced. Is this a common problem on properties of this age and how can I irradicate it? Trying to seal the small gaps between boards would be a difficult process and in any case I would like to access the floorvoid from time to time to check on timbers and under floor services etc. Heavy carpet and underlay would perhaps solve the problem but would defeat the beauty of the exposed boards. is there perhaps an infill or insulation that could be laid in the floor?
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MUSTY SMELL
- Thread starter michael
- Start date
Have you checked that the air bricks that ventilate the underfloor void haven't got clogged or covered in some way?
If there's a decent current of fresh air passing through you shouldn't be getting a musty smell (though there will be some ventilation of the room above, via the gaps between the boards).
If there's a decent current of fresh air passing through you shouldn't be getting a musty smell (though there will be some ventilation of the room above, via the gaps between the boards).
Gervase
Member
- Messages
- 1,500
- Location
- North London
You need as much air as possible going under the floor, so leave things as they are vis-a-vis the airbricks. By all means fill the gaps between the boards, and there are many ways of doing that, from cutting thin strips from a one-inch board with a bandsaw to papier mache to natty little plastic strips that are folded into the gap and expand to fit it.
But if there's a musty smell it may mean that the soil under the floor is getting overly damp, and that's something to avoid.
What are the ground levels like outside? Ideally they should be below the soil levels under your floor. If they're above, damp may be migrating inwards.
How musty is the smell? Does it smell 'mushroomy'? Are you able to lift any of the boards to check for fungal attack? Unlikely, I know, given that your timbers have been treated, but it's always helpful to be able to rule out every contingency.
How's your plumbing? Any leaks below floor level?
Have you use any rodent poison lately? Is the mustiness the result of a mummified mouse? I've been there - don't laugh! My then wife nearly went bonkers trying to work out the source of the smell...
But if there's a musty smell it may mean that the soil under the floor is getting overly damp, and that's something to avoid.
What are the ground levels like outside? Ideally they should be below the soil levels under your floor. If they're above, damp may be migrating inwards.
How musty is the smell? Does it smell 'mushroomy'? Are you able to lift any of the boards to check for fungal attack? Unlikely, I know, given that your timbers have been treated, but it's always helpful to be able to rule out every contingency.
How's your plumbing? Any leaks below floor level?
Have you use any rodent poison lately? Is the mustiness the result of a mummified mouse? I've been there - don't laugh! My then wife nearly went bonkers trying to work out the source of the smell...
Many thanks for all the advice. I should reiterate that this smell is not continuous; it just occurs from time to time and would seem to be subject to climatic conditions such as wind rain etc.
The layout and situation of the property is quite difficult to describe but necessary when trying to analyse this smell problem. I will try my best.
The property is situated in a coastal resort at the top of a residential street which runs up the side of a steep hill. Consequently the street in front of us falls sharply away from the property and at the back of the property we face onto the hill which is all parkland. Subsoil is clay on sandstone.
50 % of the rear wall of the property is below ground i.e. street level is half way up the rear elevation of the property. This street comprises of the pavement running adjacent to the rear elevation then the kerb and small tarmac road. On the other side of the road is an 8 or 9 ft stone retaining wall containing the hill and parkland and this has a number of drainage pipes which directs water running off the hill into a road gully.
We have had no damp problems or smells in this wall or the adjacent rooms which are all carpeted. The under floor soil is relatively dry albeit a slightly sandy and grey colour but there has been evidence of salts on the surface.
It is difficult to establish the construction of this rear wall below ground but it would appear to be thicker than the 9” solid wall on the rest of the property and perhaps containing a void. There was originally only one air brick in this wall up at street level and I had a further 4 air bricks installed at equal distances. There was evidence of a little draft when these bricks were installed so maybe there is a void which with the additional airbricks will be improving the ventilation.
Running along the base of this rear wall, within the property, are a number of heavy metal floor grills set into the floor boards with the carpet cut around to expose them. Each of these grills is about 3ft x 6””
The room with the occasional smell is some 12ft away from this rear wall. It is the only room that is uncarpeted. It is separated from the other rooms by partitioning and consequently the floor void runs under all the rooms continuously. The room with the occasional smell is some 54ft long x 15ft wide. 30 ft of which is made up of floor boards with void under and the remaining 24ft towards the front of the property is solid floor with parquet flooring.
To the sides of this room the under floor void continues under a shower room, a kitchen and a small side door lobby up to the side elevation wall which I have added a further two air vents to bring the total on this elevation to 5.
Running in the opposite direction to the other side elevation, the floor void runs under the old chapel building which has tongue and grooved floor boards and is ventilated from the front of the building with a total of 6 air bricks. Rear ventilation in the chapel is as per the below ground wall described above plus heavy grills in the floor.
In conclusion, the void in the room with the occasional smell is effectively trapped between the rear ‘below ground’ wall described above and the solid parquet floor towards the front of the property and relies on its ventilation from air passing from the chapel floor void to one side, air passing from 5 air bricks near the kitchen on the other side, the floor grills at the rear of the building and possibly the additional air bicks installed up at street level. Maybe this isn’t enough
Mushroomy smell, I don’t know, maybe. We did discover a bit of dry rot when we first moved in but timbers, soil and adjacent brick walls were thoroughly professionally treated with gallons of water based chemicals and I haven found anything since.
Plumbing is only about 7 years old .No leaks that I know of
No evidence of rodent infestation.
This may sound crazy but thinking about it the additional ventilation that I added could coincide with the occurrence of the smell? Any ideas
The layout and situation of the property is quite difficult to describe but necessary when trying to analyse this smell problem. I will try my best.
The property is situated in a coastal resort at the top of a residential street which runs up the side of a steep hill. Consequently the street in front of us falls sharply away from the property and at the back of the property we face onto the hill which is all parkland. Subsoil is clay on sandstone.
50 % of the rear wall of the property is below ground i.e. street level is half way up the rear elevation of the property. This street comprises of the pavement running adjacent to the rear elevation then the kerb and small tarmac road. On the other side of the road is an 8 or 9 ft stone retaining wall containing the hill and parkland and this has a number of drainage pipes which directs water running off the hill into a road gully.
We have had no damp problems or smells in this wall or the adjacent rooms which are all carpeted. The under floor soil is relatively dry albeit a slightly sandy and grey colour but there has been evidence of salts on the surface.
It is difficult to establish the construction of this rear wall below ground but it would appear to be thicker than the 9” solid wall on the rest of the property and perhaps containing a void. There was originally only one air brick in this wall up at street level and I had a further 4 air bricks installed at equal distances. There was evidence of a little draft when these bricks were installed so maybe there is a void which with the additional airbricks will be improving the ventilation.
Running along the base of this rear wall, within the property, are a number of heavy metal floor grills set into the floor boards with the carpet cut around to expose them. Each of these grills is about 3ft x 6””
The room with the occasional smell is some 12ft away from this rear wall. It is the only room that is uncarpeted. It is separated from the other rooms by partitioning and consequently the floor void runs under all the rooms continuously. The room with the occasional smell is some 54ft long x 15ft wide. 30 ft of which is made up of floor boards with void under and the remaining 24ft towards the front of the property is solid floor with parquet flooring.
To the sides of this room the under floor void continues under a shower room, a kitchen and a small side door lobby up to the side elevation wall which I have added a further two air vents to bring the total on this elevation to 5.
Running in the opposite direction to the other side elevation, the floor void runs under the old chapel building which has tongue and grooved floor boards and is ventilated from the front of the building with a total of 6 air bricks. Rear ventilation in the chapel is as per the below ground wall described above plus heavy grills in the floor.
In conclusion, the void in the room with the occasional smell is effectively trapped between the rear ‘below ground’ wall described above and the solid parquet floor towards the front of the property and relies on its ventilation from air passing from the chapel floor void to one side, air passing from 5 air bricks near the kitchen on the other side, the floor grills at the rear of the building and possibly the additional air bicks installed up at street level. Maybe this isn’t enough
Mushroomy smell, I don’t know, maybe. We did discover a bit of dry rot when we first moved in but timbers, soil and adjacent brick walls were thoroughly professionally treated with gallons of water based chemicals and I haven found anything since.
Plumbing is only about 7 years old .No leaks that I know of
No evidence of rodent infestation.
This may sound crazy but thinking about it the additional ventilation that I added could coincide with the occurrence of the smell? Any ideas
Paul Hopper
Member
- Messages
- 98
- Location
- Leics/Notts/Derbys border
Michael
Follow up the areas apparently once subject to dry rot..
It can be a s*d to get rid of, though removal of its moisture source helps
enormously.
If you can get under the floor to reach the affected area give it a very firm probe.
keep us posted
Paul
Follow up the areas apparently once subject to dry rot..
It can be a s*d to get rid of, though removal of its moisture source helps
enormously.
If you can get under the floor to reach the affected area give it a very firm probe.
keep us posted
Paul
thiambal
Member
- Messages
- 464
- Location
- Walmer, Kent
I have a very similar problem with my late victorian terraced house. When we moved in the board in the front room has been replaced - evidently because of some rot in them. They have however been replaced with new boards (not t&g) and all the timber treated with preservative.
The room is on 10'x14' with a small bay to the front of the house. There is about a 12-18" drop under the boards. There is one air brick in the centre of the bay but the ground outside is only a matter of an inch or less below the air brick.
I have the same musty smell which is particularly noticable when the rooms has been shut up for the day.
I am going to did out the front garden to drop the level down there - but practically it cannot go below the level of the earth inside the house.
I am wondering about have additional air bricks in the front to improve ventilation?
I would be keen to know if you come up with a solution to your problem!
The room is on 10'x14' with a small bay to the front of the house. There is about a 12-18" drop under the boards. There is one air brick in the centre of the bay but the ground outside is only a matter of an inch or less below the air brick.
I have the same musty smell which is particularly noticable when the rooms has been shut up for the day.
I am going to did out the front garden to drop the level down there - but practically it cannot go below the level of the earth inside the house.
I am wondering about have additional air bricks in the front to improve ventilation?
I would be keen to know if you come up with a solution to your problem!
Paul, I havent had a chance to reinspect the old dry rot infected areas yet but worst area affected at the time was under the kitchen floor (again professionally dealt with) and there have been no smells or problems in this area since.
I dont remember there ever being a smell when we first moved in 3 years ago even though we subsequently discovered and dealt with a few small areas of dry rot.(i.e that rot was not giving off a smell)
Every time I get the chance to lift a floorboard or two such as recently when we had some electrical work done, I always stick my head down into the void and have a good look around with the torch. I havent found anything out of order yet.
Are there any electronic devices on the market for detecting the precise location of smells (like a metal detector type thing) This would make life much easier than trying to locate any problems visually under our very large floor area.
As previously mentioned this musty (earthy) smell is not continuous and we havent experienced it for the last 4 weeks maybe because of the very hot dry weather we've been experiencing of late.
Thanks for your interest
I dont remember there ever being a smell when we first moved in 3 years ago even though we subsequently discovered and dealt with a few small areas of dry rot.(i.e that rot was not giving off a smell)
Every time I get the chance to lift a floorboard or two such as recently when we had some electrical work done, I always stick my head down into the void and have a good look around with the torch. I havent found anything out of order yet.
Are there any electronic devices on the market for detecting the precise location of smells (like a metal detector type thing) This would make life much easier than trying to locate any problems visually under our very large floor area.
As previously mentioned this musty (earthy) smell is not continuous and we havent experienced it for the last 4 weeks maybe because of the very hot dry weather we've been experiencing of late.
Thanks for your interest
Paul Hopper
Member
- Messages
- 98
- Location
- Leics/Notts/Derbys border
Michael
several thoughts occur.
As you describe the site you seem to have a roadway behind you at a higher level than your ground floor,
You seem to have a solid block across the front of your building in the form of your Kitchen floor. which is I assume comparable or above the ground level (roadway) at the front.
The word "chapel " strikes terror into me heart! Sadly these have almost always been short of maintenance especially in the sub floor areas,mainly because no one person has been reponsible for their upkeep often for many years.
further.. could there be surface water drainage below your rear roadway?
Try to open up a decent trapdoor into the floor area and set up a safe lead light , wait until it smells again and then, suitably dressed in mask and overalls and armed with hammer, probe, torch, lunch, gloves etc,, set out on a voyage of discovery.
As regards methods of assessing smells electronically, i am not aware of any, perhaps others may have ideas on this. The average (if such there be!) damp meter only shows resistance in a wall probably a bit higher in a wt one than in a dry one, They are a useful tool but need a bit of understanding. They were also originally intended for checking the moisture content in timber so do not rely entirely on a high reading.
You could try the meter in the underside of the floor joists.. this may give you some idea of how wet the sub floor joists are
You may find that locating the source will take some considerable detective work.
Good luck!
Paul
several thoughts occur.
As you describe the site you seem to have a roadway behind you at a higher level than your ground floor,
You seem to have a solid block across the front of your building in the form of your Kitchen floor. which is I assume comparable or above the ground level (roadway) at the front.
The word "chapel " strikes terror into me heart! Sadly these have almost always been short of maintenance especially in the sub floor areas,mainly because no one person has been reponsible for their upkeep often for many years.
further.. could there be surface water drainage below your rear roadway?
Try to open up a decent trapdoor into the floor area and set up a safe lead light , wait until it smells again and then, suitably dressed in mask and overalls and armed with hammer, probe, torch, lunch, gloves etc,, set out on a voyage of discovery.
As regards methods of assessing smells electronically, i am not aware of any, perhaps others may have ideas on this. The average (if such there be!) damp meter only shows resistance in a wall probably a bit higher in a wt one than in a dry one, They are a useful tool but need a bit of understanding. They were also originally intended for checking the moisture content in timber so do not rely entirely on a high reading.
You could try the meter in the underside of the floor joists.. this may give you some idea of how wet the sub floor joists are
You may find that locating the source will take some considerable detective work.
Good luck!
Paul