roof collapse walthamstow

From that and a picture from a different angle in another report, it looks to me as if the apex support beam has failed. Closing the area for

Possibly someone removed a weight bearing wall in the top floor flat.

Tim

ha ha diyers probably took away the box and oxters...ha ha serves then right...used to see that all the time....

It looks if the neigbouring house may have same problem with the ridge bowing in the middle of the span.

Around my way building control now usually requires a few more supports to be added to the roof structure on older properties before a new roof is installed.

The sagging of the roof ridge in the middle of the span can still be seen in many terrace properties around my way.

here is what you do before a building collaspses......

Isn't this common if you replace the original slates with heavier tiles?

It would be unusual for a load bearing wall to continue into the loft, to support the apex beam. There are no signs of a wall having been bonded into the dividing wall in this picture:

Another view:

A local roof is in slate, and so wondering if this roof was never designed to take concrete tiles?

Somewhat of an urban myth - slates are heavy. Depending on the thickness of slate a concrete tile roof may be the same weight or even lighter.

If it was anything like my 1908 property the ends of the purlins may not of have been properly supported on the party walls. In my house one end missed the brick supports in the wall by a couple of feet and therefore completely unsupported at the very end. Two of the supports were rebuilt soon after this discovery

I wonder if part of the problem when replacing a roof on an old property is that the old dried out timber assumes a new position when stripped of all the old slates/battens that were also holding the structure in place.

Or the new build on one side replaced the party wall at roof level but neglected to provide supports for a purlin next door?

Failure of a ridge on a balanced apex roof would be fairly uncommon I would have thought. There does not appear to be a large dormer on the rear that could have left it under excess load.

If someone had removed the lateral restraint at the base of the rafters (usually provided by the ceiling joists) so they could spread and pull off the wall plate though, that could do it.

Seems to be a common over reaction these days :-)

More likely builders since it sounds like a HMO conversion...

(Us diyers tend to take more care when it's our roof, and we are the ones it's going to fall on!)

And again in English?

Struts, from ceiling joists to rafters?

what?

ATTIC UPRIGHT / OXTER WALL – is the part of an attic truss that forms the stub internal wall. “Oxter” is a Scottish term for an armpit, so with a little imagination you may see the reference. The size of an attic upright / oxter wall in an attic truss is usually around 1.2m high. As it is formed as a part of the attic truss, the wall structure is in-situ as soon as the truss is erected.

Presumably the oxters support the rafters at the point of potential maximum sag?

Has the load on an oxter been measured, or calculated or modelled?

Where is the purlin that I would expect to support the rafters about midway up their length ?. Building a roof like that without purlins would require far stronger rafters, which would be unusual for that type of property ?. Also replacing the original slate roof with tiles would impose and even heavier down force.

The original photo didn't seem to show a dormer or any velux windows.

Struts from a load bearing structure vertically up to a *purlin* surely ?. Then the purlin supports the mid point of the rafters which can then use much smaller timbers.