Gus Potter

I was generalising. I makes no difference as you should know. The condensate seal trap works the same way. It does not matter if it is internal or external to the boiler. The fact is that if water backs up in the rain water pipe it's going to piss out inside the house big time and wet all the electrics for example. . Of course it triggers a cut out of the boiler but where does the over pressure from the rain water pipe go then. If the rain water pipe backs up then the pressure head is at gutter level say that is 2.5 to 3.0m head. In the round the thing stinks. This sounds like a bit of a straw man argument. Are you serious? A Pressure relief valve into a condensate pipe? Can you explain in lay terms?

Hiya. To provide a bit of context, much of my initial SE training and Masters research was on portal frames. I know enough to make a contribution on this type of design. Here is my offer. You can call me on the phone on 0771 308 1597 for a 15 -30 min chat. It's free for BH folks! This forms part of my pro bono work that is good for my soul, my primary qualification is in Civil Engineering, you work for the public. Text me first so I know it's you. I'm pretty deaf so sometimes miss calls. I use my own name and can be easily found on the internet.. I get some interesting calls and offers, these range from "massages" to lots of "financial" offers and other "stuff" that actually breaks up my day, hence me filtering calls. The section sizes you quote might be dependent on your eaves height, wind loading and the types of finishes. That the best I can do for now.

Ok @Nickfromwales and Karen. To expand, my mum is 95. The following happend to my neighbour. The rainwater down pipe got blocked and the water backed up. The water then flooded back up the discharge pipe, over flowed the tundish inside, soaked the electrical fuse box, soaked the floors. Karen. You are right on this. If you need some help then happy to chip in with a draft text to support a complaint as I'm sure @Nickfromwales will also do.

I agree how on earth can this be justified. Now they might say well ok we are following the gas regs we have the right tun dish inside so the over pressure is discharged. Putting my SE hat on I'll say if that pipe freezes you can't have water pouring into the structure. Now the building regs support my statement. It's a disgrace. Between you and I @Nickfromwaleswe could make hay with this compliant! And to do this to a person of this age is appalling. My own view is that there needs to be a bit of punishment element to discourage others. The way you actually win this argument is to use a technique that I deploy against say the NHBC for example. You might have a valid case for saying it's a structural safety issue. Then your case will get elevated up the chain. The structural issue is that if the pipe freezes water will potentially get into the structure and cause structural damage. You might argue that it might stain your flooring..but that is subjective, but as an SE if I argue the safety case they start to maybe wake up and smell the coffee. Karen, be persistent. What is happening here is gate keeping, they deny, delay, defend.

Historic bricks vary a lot in size, but that is the attraction. If the brickwork is essentially non load bearing then your options expand a lot. But BC might ask about their frost resistance. If they are particularly permeable then they may ask for a bespoke DPC type detail. It's horribly frustrating at times as a designer , especially when trying to recycle materials and do the right thing environmentally.

Call your SE and they may fix your dilemma. Why do you think the steels are oversized? What you are doing is actually quite complex and fraught with difficulty in terms of the fire design. Your SE is best placed to help.

Here is a bit of a good news story. There are two common ways of fire protecting steels. We can box it in with steel angles and say Fire Line plaster board or we can paint with intumescent paint. But BC often ask up front for a specification on the paint system. I wrote this morning to Rawlins Paints the following: Dear technical Department. I'm seeking assistance with a paint specification for steelwork fire protection and certificate / data sheets for a building warrant submission. Attached is a drawing showing the proposed steelwork. The project is a single story domestic house extension with a pitched concrete tiled roof in Scotland. The requirements are: 1/ Level of fire protection required 30minutes ( short duration). 2/ Section sizes are 178 x 102 UB19 S275 or S355 and 152 x 89 UB16 S275. 3/ The load ratio for the 178 x 102UB 19's is 35% and the load ratio for the 152 x 89 U16 is 50% 4/ Exposure to fire: Three sides are exposed; bottom flange and sides. The top flange has a 145 x 45 timber wall plate shot fired to it to support timber rafters. 5/ The beams are orientated in the vertical plane (top flanges upper most), loaded vertically downwards about their major axis. 6/ Quantities:The steelwork lengths are shown on the drawing. 7/ Steel design code is BS5950 part 1: 2000 8/ Exposure to weather: All steelwork is within the weatherproof envelope of the building. Thus dry conditions. No chemical exposure is required. 9/ Application of paint is to be on site, ideally brush applied. This can be done before fixing of the wall plates. By the close of business today I had a paint specification and an undertaking to supply the certification certificate provided we use their product of course. That is a fantastic service! Now for folk on BH. I'm putting these steels in awkward places, thus to box them in is going to be very labour intensive and that is very costly. On a technical note in item 3. I refer to what is called the load ratio. The steel sizes on this project are sized on how much they deflect in service. That stops cracking in ceilings for example. But in a fire we just want to make sure they don't fall down. The load ratio is the load on the steels in a fire compared with the steel beam ultimate strength / buckling strength. Long steel beam design is often governed by buckling, it twists and distorts first. That is why we tie floors into the steel beams for example to prevent the twisting in normal use. But during a fire that contribution can get lost as the floor / roof can burn away to the extent that it stops restraining the beams. Thus the load ratio is based on the strength of the beam when say part of the restraining floor or roof burns away in less than the required fire protection time. But even so using a paint system can be very cost effective. If a beam is not fully loaded up to it maximum capacity during a fire then the intumescent paint system can be of real economic advantage. To explain roughly. If a steel beam is loaded up to it's maximum capacity then it will fail at a lower temperature. A beam can still carry a bit of load at a higher temperature and that is where the load ratio comes in. The paint acts like an insulating blanket that slows the rate the steel heats up.. and that gives us the fire duration requirement we see in the building regs. The above it intended to give you a bit of a template if asking about intumescent paints.

Fair comment and accepted.

This is very well stated. It's part of Scottish humour, "ma sides are bursting". That means I'm chuckling a lot having read this, enough to hurt myself. One part of the meaning is to say that profit is sanity, turnover is vanity. A corollary could be the way a Yorkshire Farmer conducts business.

It's not the concrete strength I was remarking on it was the shrinkage and cracking. Anyway it's done now, time will tell if it becomes a serviceability issue. You're right in that it's ok to be sceptical at times on BH, there is no benefit to new members for example if we don't put forward different views. For me I expect folk to call me out if they feel I'm barking up the wrong tree. It's healthy to do so. But there is a caveat here. Some of the eco stuff and arguments are not adult and I have a limit on my time to address some of the nonsense promoted.

You are right in that a low offer can get folks back up. In some ways if you have a plot with fab views, location etc you know has sat for a long time then there is probably challenges associated with it. This sounds counter intuitive. But in some cases it can also work if you make a high, but broadly caveat initial offer This indicates you are serious about it and have already done you research "as a lay person". The seller can see you have spent some cash to date. The objective is to get them engaged and then lead them towards what is the true value of the plot. That could be to do with services, potential land contamination etc. The benefit of doing it this way is that once engaged you educate the seller to the point where they realise that they are not selling a Rolls Royce but a potential pup and might think, hey I'll just get rid of it as the purchaser (you) has explained the true value, the risk you are willing to take on. The selling agent will also see your argument and might say.. this is the best offer you are going to get. @Square Feet "The plot is owned by a limited company so I was able to find the owner's details including age and address. " As an off the wall thought. There may be a significant tax implication to the seller. But you'll only find that out and if you help them mitigate by getting them to the table.

@MikeSharp01 Interesting stuff.. Yes it can be, if you have the will to live. I think pragmatism should prevail here and, at times I'll just need to contradict myself! for the common good. What I was referring to was what happens in the walls of the house. To explain this in lay terms and to use a qualitative example. If you have good double glazing and say overnight the house is sitting inside at 18 deg C and the temperature outside drops to 10 deg C. The outside pane of glass may end up at 6.00 am in the morning at about 11- 12 deg. Now suddenly a warm moist weather front of air blows in. You can often see condensation on the outside of the glass. This happens quite a lot in Scotland for example. If you have rubbish glazing then the outer pane will be much warmer as it gets heated from the 18 deg C air inside the house and thus you are less likely to observe this. Now if you can see that then you might ask.. well are the walls that we can't see inside doing the same. That is in summary what I referred to as reverse condensation. But this thread is not really about that. It's to do with condensation inside the house when you cool it on hot days. The fundamental questions are: 1/ How cool do you want your house on a hot day and what am I prepared to pay for that? 2/ Am I going to do something that could compromise the design of the house. This could be by causing condensation to occur in a place where it can't be easily vented out and thus promote things to rot / corrode. We spend loads of time on BH detailing air tightness and so on.. but we are always thinking (so far until say this thread) from the inside out. 3/ Am I able to accept some cooling say from my Air source heat Pump (ASHP) and treat this as a bit of free lunch. It won't be perfect but it's a good pragmatic trade off. Now for me, take any underfloor heating / ASHP or similar combination. My immediate approach is to ask, can we keep it simple, cheep to maintain and by default retain value in your house. @JohnMo sums it up for me here with practical elegance. Aren't you going down a rabbit hole of complexity for complex sake. Heat pumps like simple open flow systems, if you involve UFH you are limited to 14 to 16 Deg flow temp (depends on location), no dew point management specifically needed. Size any fan coils to operate at that flow temp. Otherwise your into electronic mixers etc. In summary there is no perfect answer. The systems are generally set up to heat the house, but can cool to some extent. But for a bit of pragmatism lets look at what could go wrong if you get condensation on the heating pipes in cooling mode. 1/ If you lag the pipes then water gas will still get in and condense. If running for a long time with adverse humidity then water will collect and run out the gaps in the insulation. Now if that happens over a ceiling it will cause staining. 2/ Much depends on how you use and respect the house. If you are boiling up pasta big time or drying washing inside then that is an issue. The building regs are set up for this, but.. 3/ We need to consider the frequency of occurrence. It's ok if from time to time you get a bit of condensation, so long as you get rid of it quickly enough then the risk of harm is low. We will quite happily take a couple of buckets of water and wash floors! That will change the humidity rapidly.

I posted some stuff a few years back about how you get, call it " reverse condensation". My post was driven as I live in Scotland. Here we get days, particularly on the west coast where the house is cooler on the inside and the Atlantic Ocean moist winds blows in. Most BH folk wrote me off as a mad Jock! It totally reverses the dew point calculation and yes you do get condensation forming on the cooler house surfaces. Now in the south of the UK you are not accustomed to this.. but if you introduce air con into a very well insulated house then this kind of reverse dew point and internal condensation is worth a thought. In structural terms the odd bit of water gas condensation is ok.. but too much and you have a problem.

I'll take you word for it that they turned up with some lose rebar and made it all good. That requires diagonal bars to transfer the shrinkage loads around the service penetrations and supplementary bars to compensate for the cut ones. My experience tells me other wise. I doubt this happened, forgive my old school sceptesism, rafts and so on are not my first "rodeo!"

But the photo shows you have happily cut the rebar without reinforcing not least diagonally to prevent cracking. You've dropped a bollock there!