Background: In the summer we had the back bedroom roof of our
victorian terraced house reroofed. It has the original rafters but
eveything else is new. It has slate/impermeablemebrane/air gap/
celotex/thinsulex/plasterboard .

The problem: On clear nights, when the temperature drops fast, the
roof starts to "crackle and pop". The sound come from all over the
ceiling and is quite loud. It's as if someone is dropping small
stones onto the roof from a great height. If you go out in the back
garden you can hear it clearly and it seems to be coming from the
slates. It does this for about 20 minutes and then it stops; last
night it began at about 11 pm (in Cambridge).

Another thing: when I went in the garden to listen, I noticed that I
could hear a similar noise from another house that also had recently
had the roof redone (by a different contractor).

Is this a well-known problem? How do I cure it? We couldn't sleep in
that room. In fact, it's so loud it wakes us up in the front bedroom!

Robert

MY whole roof replaced on a chapel conversion (slates, battens,
breather) on original joists, 18 months ago - yes, mine did that too
for the first 6 months, less so now Nighttime after a very hot sunny
day would do it too.

AFAICT it's just settling, and does diminish after a few months. In
fact with mine it was like a little wave of tinkling sounds running
back and forth across the roof.

If there was visible distortion of the roof, or loud cracks like an
imminent failure of a timber, I'd worry.

Otherwise, best not to focus on it - it will only seem louder and more
intrusive because you do.

I'm also getting creaks from the 6 velux windows I put in whilst
having the roof done, or rather from the paneling around them. This
seems to be because of differential thermal movement between the
timber inside the insulation, and the joists outside.

These aren't going away, so I think I'm going to have to change the
way I've paneled in between the joists/velux on the outside and the
studwork inside, so one side has a sliding joint.

On Feb 15, 9:50*am, " wrote:
MY whole roof replaced on a chapel conversion (slates, battens,
breather) on original joists, 18 months ago - yes, mine did that too
for the first 6 months, less so now Nighttime after a very hot sunny
day would do it too.

AFAICT it's just settling, and does diminish after a few months. In
fact with mine it was like a little wave of tinkling sounds running
back and forth across the roof.

I wonder if it's ice freezing the slates together but then cracking as
further cold makes everything contract and move a little. I can't
think that just shrinkage would make such pronounced "crack" sounds.
Nothing structural seems to be moving. At first I was worried it was
frost heave moving the walls about but it doesn't seem to be.

The roof pitch is very shallow (16 degrees) and this might encourage
water to get held between the slates I suppose.

I do hope it stops after a while! The room is unusable for sleeping.

Robert

On Feb 15, 7:40*pm, RobertL wrote:
On Feb 15, 9:50*am, " wrote:

MY whole roof replaced on a chapel conversion (slates, battens,
breather) on original joists, 18 months ago - yes, mine did that too
for the first 6 months, less so now Nighttime after a very hot sunny
day would do it too.

AFAICT it's just settling, and does diminish after a few months. In
fact with mine it was like a little wave of tinkling sounds running
back and forth across the roof.

I wonder if it's ice freezing the slates together but then cracking as
further cold makes everything contract and move a little. * I can't
think that just shrinkage would make such pronounced "crack" sounds.
Nothing structural seems to be moving. *At first I was worried it was
frost heave moving the walls about but it doesn't seem to be.

The roof pitch is very shallow (16 degrees) and this might encourage
water to get held between the slates I suppose.

I do hope it stops after a while! *The room is unusable for sleeping.

Robert

Are you sure there slates as slates dont go down to 18 degs. The
recommended lowest pitch for slates is 22 1/2 degs. 24" x 12" with 4"
head lap. On the other hand some single lap interlocking slates and
tiles do go down to 17 1/2 degs.

On Feb 15, 8:44*pm, Kipper at sea wrote:
On Feb 15, 7:40*pm, RobertL wrote:





On Feb 15, 9:50*am, " wrote:

MY whole roof replaced on a chapel conversion (slates, battens,
breather) on original joists, 18 months ago - yes, mine did that too
for the first 6 months, less so now Nighttime after a very hot sunny
day would do it too.

AFAICT it's just settling, and does diminish after a few months. In
fact with mine it was like a little wave of tinkling sounds running
back and forth across the roof.

I wonder if it's ice freezing the slates together but then cracking as
further cold makes everything contract and move a little. * I can't
think that just shrinkage would make such pronounced "crack" sounds.
Nothing structural seems to be moving. *At first I was worried it was
frost heave moving the walls about but it doesn't seem to be.

The roof pitch is very shallow (16 degrees) and this might encourage
water to get held between the slates I suppose.

I do hope it stops after a while! *The room is unusable for sleeping.

Robert

Are you sure there slates as slates dont go down to 18 degs. The
recommended lowest pitch for slates is 22 1/2 degs. 24" x 12" *with 4"
head lap. On the other hand some single lap interlocking slates and
tiles do go down to 17 1/2 degs.- Hide quoted text -


yes, i am sure they are plain slates. It was an existing roof
(victorian back of house) with a very shallow pitch and BC allowed it
with a completely impermeable membrane under the slates. there is a
50mm air gap under this membrane but I guess there can be wetness
between it and the slates which could freeze.

Robert

Hi Robert,

We extended our house over a year ago, installing a new section of slate roof. We are experiencing the same "snap, crackle, pop" sound you described whenever the temperature drops at night. We now sleep in the old part of the house whenever it is cold. Did your roof settle down eventually or are we going to have to do something to fix the problem?

Douglas

On Monday, February 15, 2010 9:19:18 AM UTC, RobertL wrote:
Background: In the summer we had the back bedroom roof of our
victorian terraced house reroofed. It has the original rafters but
eveything else is new. It has slate/impermeablemebrane/air gap/
celotex/thinsulex/plasterboard .

The problem: On clear nights, when the temperature drops fast, the
roof starts to "crackle and pop". The sound come from all over the
ceiling and is quite loud. It's as if someone is dropping small
stones onto the roof from a great height. If you go out in the back
garden you can hear it clearly and it seems to be coming from the
slates. It does this for about 20 minutes and then it stops; last
night it began at about 11 pm (in Cambridge).

Another thing: when I went in the garden to listen, I noticed that I
could hear a similar noise from another house that also had recently
had the roof redone (by a different contractor).

Is this a well-known problem? How do I cure it? We couldn't sleep in
that room. In fact, it's so loud it wakes us up in the front bedroom!

Robert

I expect it's the fresh slates rubbing against each other as they contract in the cold. There must be thousands of little points of contact between them all. These will slowly wear down over time as slate is relatively soft, until it goes quiet.