Roof structure question???

[gaz1]

I might be tempted to try something like this:

Bolt firmly into wall, gradually apply some pressure with the push bolt.

Yeah, offset the anchor bolts so the lifting bolt can pass through.

your first comment was spot on

this comment above is dream on not a chance in hell of spinning it back with all those rafter nails that includes taking a sledge hammer in the loft and whacking the beam with the sledge hammer to spin it back while you have pressure on each side to spin it push it back

 

[gaz1]

I just remembered now you've said that, I did the same 4 years ago on the other end.
View attachment 364799

whilst this was a bodge its also under designed to hold up the beam as you should have used a wider beam and thicker beam for more support and strength

at first point id have agreed and probably done the same but with both done the same its a big no no

the fact you had supported it was the best thing that you could have done

just to note a point that beam is being held up by its rafter beams theyve already pulled out 1-2" so not much left holding them up if the beam gives your dead if your under it its simple as its really heavy and will cause loads of damage

 

[maroon]

How about making a HD version of a joist hanger in 3"x3"angle , it could be cross bolted through the purlin and anchor bolted to the wall. just thoughts

Bob

i wouldn't bolt through the beam just let it sit. box round it few rawl bolts into the wall. 3-4mm if you wanted to do something about it.

i'd just leave it tbh. it's held the roof up long enough as is.

 

[roblane65]

70ish year old roof it will have settled where ever it wants to by now . If there's no significant signs of movement ( that's the important bit ) I wouldn't be overly worried , Over the years I've seen plenty worse than that , are the rafters still tight to purlin ? are there any signs of the skewed nails pulling out ? if not then just put a prop underneath as you've done the other end and as a brace use a 5" x 2" vee each end and wedge it between the two perlins horizontal and fix to the brick work and have a good nights sleep . What ever you do now is just belt and braces to make sure it can't move anywhere in the future . whatever you decide to do don't prop the purlin off the ceiling rafters without making sure they are also supported in the room below .

 

[Morrisman]

So much melodrama. That piece of wire is holding it up perfectly adequately.

 

[Screwdriver]

Looking at that I would say that will twist the purlin anti clockwise

It's definitely been built like that. All the purlins are fixed the same as far as I've seen.

You don't have to jack it up, just get some pressure on if if you really think it's moving or liable to slip. With older buildings you really need to be careful with wedges which can generate enormous forces very easily. I cracked a wall in half once just by banging in a wedge. With a bolt you can moderate whatever pressure you feel is required and if it has shifted, you might even shift it back over time (carefully!)

Like I said earlier, first you really want to establish the overall condition of the roof. Hard to believe it was installed like that but it is entirely possible I guess. Should be some obvious signs of movement if it has shifted but as someone has pointed out, it does look as if the birdsmouth has been firmly nailed in place so the offset wall stake is doing a perfectly good job resisting gravity.

 

[dobbslc]

How about making a HD version of a joist hanger in 3"x3"angle , it could be cross bolted through the purlin and anchor bolted to the wall. just thoughts

Bob

Ooo good idea! I can then do so welding

 

[dobbslc]

So much melodrama. That piece of wire is holding it up perfectly adequately.

Well in a way it tells it hasn't moved much in the last 10-15 years when that alarm cable was installed as it's still straight!

 

[reb78]

Well in a way it tells it hasn't moved much in the last 10-15 years when that alarm cable was installed as it's still straight!

Nah. Your house is going to fall down. Might as well sell up and knock it down before it falls!

 

[dobbslc]

Like I said earlier, first you really want to establish the overall condition of the roof. Hard to believe it was installed like that but it is entirely possible I guess. Should be some obvious signs of movement if it has shifted but as someone has pointed out, it does look as if the birdsmouth has been firmly nailed in place so the offset wall stake is doing a perfectly good job resisting gravity.

The condition seems to be pretty good condition with no noticeable sagging or movement, the purlin is still pretty square to the rafters.
It was definitely build like this ,post war slap dash I suppose
Well done spotting the nails! I couldn't see them in the loft, the flash must have highlighted them, if they haven't twisted out maybe the block was put in like that?
Mmm decisions
Make a metal brace like @8ob says or a bigger birds mouth timber one.
The timber one will be much quicker the metal one more fun!

 

[Pigeon_Droppings2]

Make a metal brace like @8ob says or a bigger birds mouth timber one.

If the nails are in good condition then maybe that's how it was made?...the loads really depend on how the forces are transmitted down to the central wall (assuming it's the same design as mine)...do you have 1 central brace down to the middle or are there more for example?

If you are worried maybe you could brace the two purlins across the back wall with a joist bolted into the wall...suitably cut to match the purlin. I really wouldn't be jacking things up if it were me....if you just lock it into position you aren't doing any damage.

 

[James1979]

Could always get a structural engineer to look. Instead of a welding forum

I know we have lots of people to who have different skills and are all trying to help, but if I thought my house may collapse I know who I’d ask…

 

[dobbslc]

Could always get a structural engineer to look. Instead of a welding forum

Nah!

 

[dobbslc]

If the nails are in good condition then maybe that's how it was made?...the loads really depend on how the forces are transmitted down to the central wall (assuming it's the same design as mine)...do you have 1 central brace down to the middle or are there more for example?

If you are worried maybe you could brace the two purlins across the back wall with a joist bolted into the wall...suitably cut to match the purlin. I really wouldn't be jacking things up if it were me....if you just lock it into position you aren't doing any damage.

There are four 4x4" diagonal braces going from each perlin plus the wall end blocks and pegs. The braces are located on a brick wall.
Bracing across the prelims wont work as the bedrooms are in between and both sides have a chimney breast in the way!

 

[roofman]

Identical roof construction to my bungalow...that's been a 1950,s botch by the builders, you be amazed at what i see in roof spaces by builders of the 60,s and 70,s also...that timber should be in the wall

 

[dobbslc]

Here's some photos from 4 years ago when I replaced the shonky floors...
Not great for showing the roof trusses etc but you can see roughly how it's built

 

[dobbslc]

Identical roof construction to my bungalow...that's been a 1950,s botch by the builders, you be amazed at what i see in roof spaces by builders of the 60,s and 70,s also...that timber should be in the wall

Were your timbers in the wall?
How would you go about fixing this?

 

[dobbslc]

Sorry one of those pictures is of the water tank

 

[roofman]

Were your timbers in the wall?
How would you go about fixing this?

yes mine are in the wall...cheapest and fastest way would be a couple of 10mm plates same width as timber bolted to the sides and nibbed into the wall and bricked around...tbh that timber is to stop roof spars sagging and give a bit of rigidity to the roof as a whole.

 

[brightspark]

yes mine are in the wall...cheapest and fastest way would be a couple of 10mm plates same width as timber bolted to the sides and nibbed into the wall and bricked around...tbh that timber is to stop roof spars sagging and give a bit of rigidity to the roof as a whole.

the best and easiest solution .use an acro prop as well